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Text file src/cmd/compile/internal/ssa/_gen/ARM64.rules

Documentation: cmd/compile/internal/ssa/_gen

     1// Copyright 2016 The Go Authors. All rights reserved.
     2// Use of this source code is governed by a BSD-style
     3// license that can be found in the LICENSE file.
     4
     5(Add(Ptr|64|32|16|8) ...) => (ADD ...)
     6(Add(32|64)F ...) => (FADD(S|D) ...)
     7
     8(Sub(Ptr|64|32|16|8) ...) => (SUB ...)
     9(Sub(32|64)F ...) => (FSUB(S|D) ...)
    10
    11(Mul64 ...) => (MUL ...)
    12(Mul(32|16|8) ...) => (MULW ...)
    13(Mul(32|64)F  ...) => (FMUL(S|D) ...)
    14
    15(Hmul64  ...) => (MULH ...)
    16(Hmul64u ...) => (UMULH ...)
    17(Hmul32  x y) => (SRAconst (MULL <typ.Int64> x y) [32])
    18(Hmul32u x y) => (SRAconst (UMULL <typ.UInt64> x y) [32])
    19(Select0 (Mul64uhilo x y)) => (UMULH x y)
    20(Select1 (Mul64uhilo x y)) => (MUL x y)
    21
    22(Div64 [false] x y) => (DIV  x y)
    23(Div32 [false] x y) => (DIVW x y)
    24(Div16 [false] x y) => (DIVW (SignExt16to32 x) (SignExt16to32 y))
    25(Div16u x y) => (UDIVW (ZeroExt16to32 x) (ZeroExt16to32 y))
    26(Div8   x y) => (DIVW  (SignExt8to32  x) (SignExt8to32  y))
    27(Div8u  x y) => (UDIVW (ZeroExt8to32  x) (ZeroExt8to32  y))
    28(Div64u ...) => (UDIV  ...)
    29(Div32u ...) => (UDIVW ...)
    30(Div32F ...) => (FDIVS ...)
    31(Div64F ...) => (FDIVD ...)
    32
    33(Mod64 x y) => (MOD x y)
    34(Mod32 x y) => (MODW x y)
    35(Mod64u ...) => (UMOD ...)
    36(Mod32u ...) => (UMODW ...)
    37(Mod(16|8)  x y) => (MODW  (SignExt(16|8)to32 x) (SignExt(16|8)to32 y))
    38(Mod(16|8)u x y) => (UMODW (ZeroExt(16|8)to32 x) (ZeroExt(16|8)to32 y))
    39
    40// (x + y) / 2 with x>=y    =>    (x - y) / 2 + y
    41(Avg64u <t> x y) => (ADD (SRLconst <t> (SUB <t> x y) [1]) y)
    42
    43(And(64|32|16|8) ...) => (AND ...)
    44(Or(64|32|16|8)  ...) => (OR ...)
    45(Xor(64|32|16|8) ...) => (XOR ...)
    46
    47// unary ops
    48(Neg(64|32|16|8) ...) => (NEG ...)
    49(Neg(32|64)F     ...) => (FNEG(S|D) ...)
    50(Com(64|32|16|8) ...) => (MVN ...)
    51
    52// math package intrinsics
    53(Abs         ...) => (FABSD   ...)
    54(Sqrt        ...) => (FSQRTD  ...)
    55(Ceil        ...) => (FRINTPD ...)
    56(Floor       ...) => (FRINTMD ...)
    57(Round       ...) => (FRINTAD ...)
    58(RoundToEven ...) => (FRINTND ...)
    59(Trunc       ...) => (FRINTZD ...)
    60(FMA       x y z) => (FMADDD z x y)
    61
    62(Sqrt32 ...) => (FSQRTS ...)
    63
    64(Min(64|32)F ...) => (FMIN(D|S) ...)
    65(Max(64|32)F ...) => (FMAX(D|S) ...)
    66
    67// lowering rotates
    68// we do rotate detection in generic rules, if the following rules need to be changed, check generic rules first.
    69(RotateLeft8  <t> x (MOVDconst [c])) => (Or8 (Lsh8x64 <t> x (MOVDconst [c&7])) (Rsh8Ux64 <t> x (MOVDconst [-c&7])))
    70(RotateLeft8  <t> x y) => (OR <t> (SLL <t> x (ANDconst <typ.Int64> [7] y)) (SRL <t> (ZeroExt8to64 x) (ANDconst <typ.Int64> [7] (NEG <typ.Int64> y))))
    71(RotateLeft16 <t> x (MOVDconst [c])) => (Or16 (Lsh16x64 <t> x (MOVDconst [c&15])) (Rsh16Ux64 <t> x (MOVDconst [-c&15])))
    72(RotateLeft16 <t> x y) => (RORW <t> (ORshiftLL <typ.UInt32> (ZeroExt16to32 x) (ZeroExt16to32 x) [16]) (NEG <typ.Int64> y))
    73(RotateLeft32 x y) => (RORW x (NEG <y.Type> y))
    74(RotateLeft64 x y) => (ROR x (NEG <y.Type> y))
    75
    76(Ctz(64|32|16|8)NonZero ...) => (Ctz(64|32|32|32) ...)
    77
    78(Ctz64 <t> x) => (CLZ  (RBIT  <t> x))
    79(Ctz32 <t> x) => (CLZW (RBITW <t> x))
    80(Ctz16 <t> x) => (CLZW <t> (RBITW <typ.UInt32> (ORconst <typ.UInt32> [0x10000] x)))
    81(Ctz8  <t> x) => (CLZW <t> (RBITW <typ.UInt32> (ORconst <typ.UInt32> [0x100] x)))
    82
    83(PopCount64 <t> x) => (FMOVDfpgp <t> (VUADDLV <typ.Float64> (VCNT <typ.Float64> (FMOVDgpfp <typ.Float64> x))))
    84(PopCount32 <t> x) => (FMOVDfpgp <t> (VUADDLV <typ.Float64> (VCNT <typ.Float64> (FMOVDgpfp <typ.Float64> (ZeroExt32to64 x)))))
    85(PopCount16 <t> x) => (FMOVDfpgp <t> (VUADDLV <typ.Float64> (VCNT <typ.Float64> (FMOVDgpfp <typ.Float64> (ZeroExt16to64 x)))))
    86
    87// Load args directly into the register class where it will be used.
    88(FMOVDgpfp <t> (Arg [off] {sym})) => @b.Func.Entry (Arg <t> [off] {sym})
    89(FMOVDfpgp <t> (Arg [off] {sym})) => @b.Func.Entry (Arg <t> [off] {sym})
    90
    91// Similarly for stores, if we see a store after FPR <=> GPR move, then redirect store to use the other register set.
    92(MOVDstore  [off] {sym} ptr (FMOVDfpgp val) mem) => (FMOVDstore [off] {sym} ptr val mem)
    93(FMOVDstore [off] {sym} ptr (FMOVDgpfp val) mem) => (MOVDstore [off] {sym} ptr val mem)
    94(MOVWstore  [off] {sym} ptr (FMOVSfpgp val) mem) => (FMOVSstore [off] {sym} ptr val mem)
    95(FMOVSstore [off] {sym} ptr (FMOVSgpfp val) mem) => (MOVWstore [off] {sym} ptr val mem)
    96
    97// float <=> int register moves, with no conversion.
    98// These come up when compiling math.{Float64bits, Float64frombits, Float32bits, Float32frombits}.
    99(MOVDload  [off] {sym} ptr (FMOVDstore [off] {sym} ptr val _)) => (FMOVDfpgp val)
   100(FMOVDload [off] {sym} ptr (MOVDstore  [off] {sym} ptr val _)) => (FMOVDgpfp val)
   101(MOVWUload [off] {sym} ptr (FMOVSstore [off] {sym} ptr val _)) => (FMOVSfpgp val)
   102(FMOVSload [off] {sym} ptr (MOVWstore  [off] {sym} ptr val _)) => (FMOVSgpfp val)
   103
   104(BitLen64 x) => (SUB (MOVDconst [64]) (CLZ <typ.Int> x))
   105(BitLen32 x) => (SUB (MOVDconst [32]) (CLZW <typ.Int> x))
   106
   107(Bswap64 ...) => (REV ...)
   108(Bswap32 ...) => (REVW ...)
   109(Bswap16 ...) => (REV16W ...)
   110
   111(BitRev64 ...) => (RBIT ...)
   112(BitRev32 ...) => (RBITW ...)
   113(BitRev16   x) => (SRLconst [48] (RBIT <typ.UInt64> x))
   114(BitRev8    x) => (SRLconst [56] (RBIT <typ.UInt64> x))
   115
   116// In fact, UMOD will be translated into UREM instruction, and UREM is originally translated into
   117// UDIV and MSUB instructions. But if there is already an identical UDIV instruction just before or
   118// after UREM (case like quo, rem := z/y, z%y), then the second UDIV instruction becomes redundant.
   119// The purpose of this rule is to have this extra UDIV instruction removed in CSE pass.
   120(UMOD  <typ.UInt64> x y) => (MSUB <typ.UInt64> x y (UDIV <typ.UInt64> x y))
   121(UMODW <typ.UInt32> x y) => (MSUBW <typ.UInt32> x y (UDIVW <typ.UInt32> x y))
   122
   123// 64-bit addition with carry.
   124(Select0 (Add64carry x y c)) => (Select0 <typ.UInt64> (ADCSflags x y (Select1 <types.TypeFlags> (ADDSconstflags [-1] c))))
   125(Select1 (Add64carry x y c)) => (ADCzerocarry <typ.UInt64> (Select1 <types.TypeFlags> (ADCSflags x y (Select1 <types.TypeFlags> (ADDSconstflags [-1] c)))))
   126
   127// 64-bit subtraction with borrowing.
   128(Select0 (Sub64borrow x y bo)) => (Select0 <typ.UInt64> (SBCSflags x y (Select1 <types.TypeFlags> (NEGSflags bo))))
   129(Select1 (Sub64borrow x y bo)) => (NEG <typ.UInt64> (NGCzerocarry <typ.UInt64> (Select1 <types.TypeFlags> (SBCSflags x y (Select1 <types.TypeFlags> (NEGSflags bo))))))
   130
   131// boolean ops -- booleans are represented with 0=false, 1=true
   132(AndB ...) => (AND ...)
   133(OrB  ...) => (OR ...)
   134(EqB  x y) => (XOR (MOVDconst [1]) (XOR <typ.Bool> x y))
   135(NeqB ...) => (XOR ...)
   136(Not    x) => (XOR (MOVDconst [1]) x)
   137
   138// shifts
   139// hardware instruction uses only the low 6 bits of the shift
   140// we compare to 64 to ensure Go semantics for large shifts
   141// Rules about rotates with non-const shift are based on the following rules,
   142// if the following rules change, please also modify the rules based on them.
   143
   144// check shiftIsBounded first, if shift value is proved to be valid then we
   145// can do the shift directly.
   146// left shift
   147(Lsh(64|32|16|8)x64 <t> x y) && shiftIsBounded(v) => (SLL <t> x y)
   148(Lsh(64|32|16|8)x32 <t> x y) && shiftIsBounded(v) => (SLL <t> x y)
   149(Lsh(64|32|16|8)x16 <t> x y) && shiftIsBounded(v) => (SLL <t> x y)
   150(Lsh(64|32|16|8)x8  <t> x y) && shiftIsBounded(v) => (SLL <t> x y)
   151
   152// signed right shift
   153(Rsh64x(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRA <t> x y)
   154(Rsh32x(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRA <t> (SignExt32to64 x) y)
   155(Rsh16x(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRA <t> (SignExt16to64 x) y)
   156(Rsh8x(64|32|16|8)  <t> x y) && shiftIsBounded(v) => (SRA <t> (SignExt8to64 x) y)
   157
   158// unsigned right shift
   159(Rsh64Ux(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRL <t> x y)
   160(Rsh32Ux(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRL <t> (ZeroExt32to64 x) y)
   161(Rsh16Ux(64|32|16|8) <t> x y) && shiftIsBounded(v) => (SRL <t> (ZeroExt16to64 x) y)
   162(Rsh8Ux(64|32|16|8)  <t> x y) && shiftIsBounded(v) => (SRL <t> (ZeroExt8to64 x) y)
   163
   164// shift value may be out of range, use CMP + CSEL instead
   165(Lsh64x64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] y))
   166(Lsh64x(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   167
   168(Lsh32x64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] y))
   169(Lsh32x(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   170
   171(Lsh16x64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] y))
   172(Lsh16x(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   173
   174(Lsh8x64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] y))
   175(Lsh8x(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SLL <t> x y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   176
   177(Rsh64Ux64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SRL <t> x y) (Const64 <t> [0]) (CMPconst [64] y))
   178(Rsh64Ux(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SRL <t> x y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   179
   180(Rsh32Ux64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt32to64 x) y) (Const64 <t> [0]) (CMPconst [64] y))
   181(Rsh32Ux(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt32to64 x) y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   182
   183(Rsh16Ux64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt16to64 x) y) (Const64 <t> [0]) (CMPconst [64] y))
   184(Rsh16Ux(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt16to64 x) y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   185
   186(Rsh8Ux64 <t> x y) && !shiftIsBounded(v)        => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt8to64 x) y) (Const64 <t> [0]) (CMPconst [64] y))
   187(Rsh8Ux(32|16|8) <t> x y) && !shiftIsBounded(v) => (CSEL [OpARM64LessThanU] (SRL <t> (ZeroExt8to64 x) y) (Const64 <t> [0]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y)))
   188
   189(Rsh64x64 x y) && !shiftIsBounded(v)        => (SRA x (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] y)))
   190(Rsh64x(32|16|8) x y) && !shiftIsBounded(v) => (SRA x (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y))))
   191
   192(Rsh32x64 x y) && !shiftIsBounded(v)        => (SRA (SignExt32to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] y)))
   193(Rsh32x(32|16|8) x y) && !shiftIsBounded(v) => (SRA (SignExt32to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y))))
   194
   195(Rsh16x64 x y) && !shiftIsBounded(v)        => (SRA (SignExt16to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] y)))
   196(Rsh16x(32|16|8) x y) && !shiftIsBounded(v) => (SRA (SignExt16to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y))))
   197
   198(Rsh8x64 x y) && !shiftIsBounded(v)        => (SRA (SignExt8to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] y)))
   199(Rsh8x(32|16|8) x y) && !shiftIsBounded(v) => (SRA (SignExt8to64 x) (CSEL [OpARM64LessThanU] <y.Type> y (Const64 <y.Type> [63]) (CMPconst [64] ((ZeroExt32to64|ZeroExt16to64|ZeroExt8to64) y))))
   200
   201// constants
   202(Const(64|32|16|8) [val]) => (MOVDconst [int64(val)])
   203(Const(32|64)F    [val]) => (FMOV(S|D)const [float64(val)])
   204(ConstNil) => (MOVDconst [0])
   205(ConstBool [t]) => (MOVDconst [b2i(t)])
   206
   207(Slicemask <t> x) => (SRAconst (NEG <t> x) [63])
   208
   209// truncations
   210// Because we ignore high parts of registers, truncates are just copies.
   211(Trunc16to8  ...) => (Copy ...)
   212(Trunc32to8  ...) => (Copy ...)
   213(Trunc32to16 ...) => (Copy ...)
   214(Trunc64to8  ...) => (Copy ...)
   215(Trunc64to16 ...) => (Copy ...)
   216(Trunc64to32 ...) => (Copy ...)
   217
   218// Zero-/Sign-extensions
   219(ZeroExt8to16  ...) => (MOVBUreg ...)
   220(ZeroExt8to32  ...) => (MOVBUreg ...)
   221(ZeroExt16to32 ...) => (MOVHUreg ...)
   222(ZeroExt8to64  ...) => (MOVBUreg ...)
   223(ZeroExt16to64 ...) => (MOVHUreg ...)
   224(ZeroExt32to64 ...) => (MOVWUreg ...)
   225
   226(SignExt8to16  ...) => (MOVBreg ...)
   227(SignExt8to32  ...) => (MOVBreg ...)
   228(SignExt16to32 ...) => (MOVHreg ...)
   229(SignExt8to64  ...) => (MOVBreg ...)
   230(SignExt16to64 ...) => (MOVHreg ...)
   231(SignExt32to64 ...) => (MOVWreg ...)
   232
   233// float <=> int conversion
   234(Cvt32to32F  ...) => (SCVTFWS ...)
   235(Cvt32to64F  ...) => (SCVTFWD ...)
   236(Cvt64to32F  ...) => (SCVTFS ...)
   237(Cvt64to64F  ...) => (SCVTFD ...)
   238(Cvt32Uto32F ...) => (UCVTFWS ...)
   239(Cvt32Uto64F ...) => (UCVTFWD ...)
   240(Cvt64Uto32F ...) => (UCVTFS ...)
   241(Cvt64Uto64F ...) => (UCVTFD ...)
   242(Cvt32Fto32  ...) => (FCVTZSSW ...)
   243(Cvt64Fto32  ...) => (FCVTZSDW ...)
   244(Cvt32Fto64  ...) => (FCVTZSS ...)
   245(Cvt64Fto64  ...) => (FCVTZSD ...)
   246(Cvt32Fto32U ...) => (FCVTZUSW ...)
   247(Cvt64Fto32U ...) => (FCVTZUDW ...)
   248(Cvt32Fto64U ...) => (FCVTZUS ...)
   249(Cvt64Fto64U ...) => (FCVTZUD ...)
   250(Cvt32Fto64F ...) => (FCVTSD ...)
   251(Cvt64Fto32F ...) => (FCVTDS ...)
   252
   253(CvtBoolToUint8 ...) => (Copy ...)
   254
   255(Round32F ...) => (LoweredRound32F ...)
   256(Round64F ...) => (LoweredRound64F ...)
   257
   258// comparisons
   259(Eq8  x y)  => (Equal (CMPW (ZeroExt8to32  x) (ZeroExt8to32  y)))
   260(Eq16  x y) => (Equal (CMPW (ZeroExt16to32 x) (ZeroExt16to32 y)))
   261(Eq32  x y) => (Equal (CMPW  x y))
   262(Eq64  x y) => (Equal (CMP   x y))
   263(EqPtr x y) => (Equal (CMP   x y))
   264(Eq32F x y) => (Equal (FCMPS x y))
   265(Eq64F x y) => (Equal (FCMPD x y))
   266
   267(Neq8   x y) => (NotEqual (CMPW (ZeroExt8to32  x) (ZeroExt8to32  y)))
   268(Neq16  x y) => (NotEqual (CMPW (ZeroExt16to32 x) (ZeroExt16to32 y)))
   269(Neq32  x y) => (NotEqual (CMPW  x y))
   270(Neq64  x y) => (NotEqual (CMP   x y))
   271(NeqPtr x y) => (NotEqual (CMP   x y))
   272(Neq(32|64)F x y) => (NotEqual (FCMP(S|D) x y))
   273
   274(Less(8|16) x y) => (LessThan (CMPW (SignExt(8|16)to32 x) (SignExt(8|16)to32 y)))
   275(Less32 x y) => (LessThan (CMPW x y))
   276(Less64 x y) => (LessThan (CMP  x y))
   277
   278// Set condition flags for floating-point comparisons "x < y"
   279// and "x <= y". Because if either or both of the operands are
   280// NaNs, all three of (x < y), (x == y) and (x > y) are false,
   281// and ARM Manual says FCMP instruction sets PSTATE.<N,Z,C,V>
   282// of this case to (0, 0, 1, 1).
   283(Less32F x y) => (LessThanF (FCMPS x y))
   284(Less64F x y) => (LessThanF (FCMPD x y))
   285
   286// For an unsigned integer x, the following rules are useful when combining branch
   287// 0 <  x  =>  x != 0
   288// x <= 0  =>  x == 0
   289// x <  1  =>  x == 0
   290// 1 <= x  =>  x != 0
   291(Less(8U|16U|32U|64U) zero:(MOVDconst [0]) x) => (Neq(8|16|32|64) zero x)
   292(Leq(8U|16U|32U|64U)  x zero:(MOVDconst [0])) => (Eq(8|16|32|64)  x zero)
   293(Less(8U|16U|32U|64U) x (MOVDconst [1])) => (Eq(8|16|32|64)  x (MOVDconst [0]))
   294(Leq(8U|16U|32U|64U)  (MOVDconst [1]) x) => (Neq(8|16|32|64) (MOVDconst [0]) x)
   295
   296(Less8U  x y) => (LessThanU (CMPW (ZeroExt8to32  x) (ZeroExt8to32  y)))
   297(Less16U x y) => (LessThanU (CMPW (ZeroExt16to32 x) (ZeroExt16to32 y)))
   298(Less32U x y) => (LessThanU (CMPW x y))
   299(Less64U x y) => (LessThanU (CMP x y))
   300
   301(Leq8  x y) => (LessEqual (CMPW (SignExt8to32  x) (SignExt8to32  y)))
   302(Leq16 x y) => (LessEqual (CMPW (SignExt16to32 x) (SignExt16to32 y)))
   303(Leq32 x y) => (LessEqual (CMPW x y))
   304(Leq64 x y) => (LessEqual (CMP x y))
   305
   306// Refer to the comments for op Less64F above.
   307(Leq32F x y) => (LessEqualF (FCMPS x y))
   308(Leq64F x y) => (LessEqualF (FCMPD x y))
   309
   310(Leq8U  x y) => (LessEqualU (CMPW (ZeroExt8to32  x) (ZeroExt8to32  y)))
   311(Leq16U x y) => (LessEqualU (CMPW (ZeroExt16to32 x) (ZeroExt16to32 y)))
   312(Leq32U x y) => (LessEqualU (CMPW x y))
   313(Leq64U x y) => (LessEqualU (CMP x y))
   314
   315// Optimize comparison between a floating-point value and 0.0 with "FCMP $(0.0), Fn"
   316(FCMPS x (FMOVSconst [0])) => (FCMPS0 x)
   317(FCMPS (FMOVSconst [0]) x) => (InvertFlags (FCMPS0 x))
   318(FCMPD x (FMOVDconst [0])) => (FCMPD0 x)
   319(FCMPD (FMOVDconst [0]) x) => (InvertFlags (FCMPD0 x))
   320
   321// CSEL needs a flag-generating argument. Synthesize a TSTW if necessary.
   322(CondSelect x y boolval) && flagArg(boolval) != nil => (CSEL [boolval.Op] x y flagArg(boolval))
   323(CondSelect x y boolval) && flagArg(boolval) == nil => (CSEL [OpARM64NotEqual] x y (TSTWconst [1] boolval))
   324
   325(OffPtr [off] ptr:(SP)) && is32Bit(off) => (MOVDaddr [int32(off)] ptr)
   326(OffPtr [off] ptr) => (ADDconst [off] ptr)
   327
   328(Addr {sym} base) => (MOVDaddr {sym} base)
   329(LocalAddr <t> {sym} base mem) && t.Elem().HasPointers() => (MOVDaddr {sym} (SPanchored base mem))
   330(LocalAddr <t> {sym} base _)  && !t.Elem().HasPointers() => (MOVDaddr {sym} base)
   331
   332// loads
   333(Load <t> ptr mem) && t.IsBoolean() => (MOVBUload ptr mem)
   334(Load <t> ptr mem) && (is8BitInt(t)  &&  t.IsSigned()) => (MOVBload ptr mem)
   335(Load <t> ptr mem) && (is8BitInt(t)  && !t.IsSigned()) => (MOVBUload ptr mem)
   336(Load <t> ptr mem) && (is16BitInt(t) &&  t.IsSigned()) => (MOVHload ptr mem)
   337(Load <t> ptr mem) && (is16BitInt(t) && !t.IsSigned()) => (MOVHUload ptr mem)
   338(Load <t> ptr mem) && (is32BitInt(t) &&  t.IsSigned()) => (MOVWload ptr mem)
   339(Load <t> ptr mem) && (is32BitInt(t) && !t.IsSigned()) => (MOVWUload ptr mem)
   340(Load <t> ptr mem) && (is64BitInt(t) || isPtr(t)) => (MOVDload ptr mem)
   341(Load <t> ptr mem) && is32BitFloat(t) => (FMOVSload ptr mem)
   342(Load <t> ptr mem) && is64BitFloat(t) => (FMOVDload ptr mem)
   343
   344// stores
   345(Store {t} ptr val mem) && t.Size() == 1 => (MOVBstore ptr val mem)
   346(Store {t} ptr val mem) && t.Size() == 2 => (MOVHstore ptr val mem)
   347(Store {t} ptr val mem) && t.Size() == 4 && !t.IsFloat() => (MOVWstore ptr val mem)
   348(Store {t} ptr val mem) && t.Size() == 8 && !t.IsFloat() => (MOVDstore ptr val mem)
   349(Store {t} ptr val mem) && t.Size() == 4 &&  t.IsFloat() => (FMOVSstore ptr val mem)
   350(Store {t} ptr val mem) && t.Size() == 8 &&  t.IsFloat() => (FMOVDstore ptr val mem)
   351
   352// zeroing
   353(Zero [0] _   mem) => mem
   354(Zero [1] ptr mem) => (MOVBstore ptr (MOVDconst [0]) mem)
   355(Zero [2] ptr mem) => (MOVHstore ptr (MOVDconst [0]) mem)
   356(Zero [4] ptr mem) => (MOVWstore ptr (MOVDconst [0]) mem)
   357(Zero [3] ptr mem) =>
   358	(MOVBstore [2] ptr (MOVDconst [0])
   359		(MOVHstore ptr (MOVDconst [0]) mem))
   360(Zero [5] ptr mem) =>
   361	(MOVBstore [4] ptr (MOVDconst [0])
   362		(MOVWstore ptr (MOVDconst [0]) mem))
   363(Zero [6] ptr mem) =>
   364	(MOVHstore [4] ptr (MOVDconst [0])
   365		(MOVWstore ptr (MOVDconst [0]) mem))
   366(Zero [7] ptr mem) =>
   367	(MOVWstore [3] ptr (MOVDconst [0])
   368		(MOVWstore ptr (MOVDconst [0]) mem))
   369(Zero [8] ptr mem) => (MOVDstore ptr (MOVDconst [0]) mem)
   370(Zero [9] ptr mem) =>
   371	(MOVBstore [8] ptr (MOVDconst [0])
   372		(MOVDstore ptr (MOVDconst [0]) mem))
   373(Zero [10] ptr mem) =>
   374	(MOVHstore [8] ptr (MOVDconst [0])
   375		(MOVDstore ptr (MOVDconst [0]) mem))
   376(Zero [11] ptr mem) =>
   377	(MOVDstore [3] ptr (MOVDconst [0])
   378		(MOVDstore ptr (MOVDconst [0]) mem))
   379(Zero [12] ptr mem) =>
   380	(MOVWstore [8] ptr (MOVDconst [0])
   381		(MOVDstore ptr (MOVDconst [0]) mem))
   382(Zero [13] ptr mem) =>
   383	(MOVDstore [5] ptr (MOVDconst [0])
   384		(MOVDstore ptr (MOVDconst [0]) mem))
   385(Zero [14] ptr mem) =>
   386	(MOVDstore [6] ptr (MOVDconst [0])
   387		(MOVDstore ptr (MOVDconst [0]) mem))
   388(Zero [15] ptr mem) =>
   389	(MOVDstore [7] ptr (MOVDconst [0])
   390		(MOVDstore ptr (MOVDconst [0]) mem))
   391(Zero [16] ptr mem) =>
   392	(STP [0] ptr (MOVDconst [0]) (MOVDconst [0]) mem)
   393
   394(Zero [32] ptr mem) =>
   395	(STP [16] ptr (MOVDconst [0]) (MOVDconst [0])
   396		(STP [0] ptr (MOVDconst [0]) (MOVDconst [0]) mem))
   397
   398(Zero [48] ptr mem) =>
   399	(STP [32] ptr (MOVDconst [0]) (MOVDconst [0])
   400		(STP [16] ptr (MOVDconst [0]) (MOVDconst [0])
   401			(STP [0] ptr (MOVDconst [0]) (MOVDconst [0]) mem)))
   402
   403(Zero [64] ptr mem) =>
   404	(STP [48] ptr (MOVDconst [0]) (MOVDconst [0])
   405		(STP [32] ptr (MOVDconst [0]) (MOVDconst [0])
   406			(STP [16] ptr (MOVDconst [0]) (MOVDconst [0])
   407				(STP [0] ptr (MOVDconst [0]) (MOVDconst [0]) mem))))
   408
   409// strip off fractional word zeroing
   410(Zero [s] ptr mem) && s%16 != 0 && s%16 <= 8 && s > 16 =>
   411	(Zero [8]
   412		(OffPtr <ptr.Type> ptr [s-8])
   413		(Zero [s-s%16] ptr mem))
   414(Zero [s] ptr mem) && s%16 != 0 && s%16 > 8 && s > 16 =>
   415	(Zero [16]
   416		(OffPtr <ptr.Type> ptr [s-16])
   417		(Zero [s-s%16] ptr mem))
   418
   419// medium zeroing uses a duff device
   420// 4, 16, and 64 are magic constants, see runtime/mkduff.go
   421(Zero [s] ptr mem)
   422	&& s%16 == 0 && s > 64 && s <= 16*64
   423	&& !config.noDuffDevice =>
   424	(DUFFZERO [4 * (64 - s/16)] ptr mem)
   425
   426// large zeroing uses a loop
   427(Zero [s] ptr mem)
   428	&& s%16 == 0 && (s > 16*64 || config.noDuffDevice) =>
   429	(LoweredZero
   430		ptr
   431		(ADDconst <ptr.Type> [s-16] ptr)
   432		mem)
   433
   434// moves
   435(Move [0] _   _   mem) => mem
   436(Move [1] dst src mem) => (MOVBstore dst (MOVBUload src mem) mem)
   437(Move [2] dst src mem) => (MOVHstore dst (MOVHUload src mem) mem)
   438(Move [3] dst src mem) =>
   439	(MOVBstore [2] dst (MOVBUload [2] src mem)
   440		(MOVHstore dst (MOVHUload src mem) mem))
   441(Move [4] dst src mem) => (MOVWstore dst (MOVWUload src mem) mem)
   442(Move [5] dst src mem) =>
   443	(MOVBstore [4] dst (MOVBUload [4] src mem)
   444		(MOVWstore dst (MOVWUload src mem) mem))
   445(Move [6] dst src mem) =>
   446	(MOVHstore [4] dst (MOVHUload [4] src mem)
   447		(MOVWstore dst (MOVWUload src mem) mem))
   448(Move [7] dst src mem) =>
   449	(MOVWstore [3] dst (MOVWUload [3] src mem)
   450		(MOVWstore dst (MOVWUload src mem) mem))
   451(Move [8] dst src mem) => (MOVDstore dst (MOVDload src mem) mem)
   452(Move [9] dst src mem) =>
   453	(MOVBstore [8] dst (MOVBUload [8] src mem)
   454		(MOVDstore dst (MOVDload src mem) mem))
   455(Move [10] dst src mem) =>
   456	(MOVHstore [8] dst (MOVHUload [8] src mem)
   457		(MOVDstore dst (MOVDload src mem) mem))
   458(Move [11] dst src mem) =>
   459	(MOVDstore [3] dst (MOVDload [3] src mem)
   460		(MOVDstore dst (MOVDload src mem) mem))
   461(Move [12] dst src mem) =>
   462	(MOVWstore [8] dst (MOVWUload [8] src mem)
   463		(MOVDstore dst (MOVDload src mem) mem))
   464(Move [13] dst src mem) =>
   465	(MOVDstore [5] dst (MOVDload [5] src mem)
   466		(MOVDstore dst (MOVDload src mem) mem))
   467(Move [14] dst src mem) =>
   468	(MOVDstore [6] dst (MOVDload [6] src mem)
   469		(MOVDstore dst (MOVDload src mem) mem))
   470(Move [15] dst src mem) =>
   471	(MOVDstore [7] dst (MOVDload [7] src mem)
   472		(MOVDstore dst (MOVDload src mem) mem))
   473(Move [16] dst src mem) =>
   474	(STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem)
   475(Move [32] dst src mem) =>
   476	(STP [16] dst (Select0 <typ.UInt64> (LDP [16] src mem)) (Select1 <typ.UInt64> (LDP [16] src mem))
   477		(STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem))
   478(Move [48] dst src mem) =>
   479	(STP [32] dst (Select0 <typ.UInt64> (LDP [32] src mem)) (Select1 <typ.UInt64> (LDP [32] src mem))
   480		(STP [16] dst (Select0 <typ.UInt64> (LDP [16] src mem)) (Select1 <typ.UInt64> (LDP [16] src mem))
   481			(STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem)))
   482(Move [64] dst src mem) =>
   483	(STP [48] dst (Select0 <typ.UInt64> (LDP [48] src mem)) (Select1 <typ.UInt64> (LDP [48] src mem))
   484		(STP [32] dst (Select0 <typ.UInt64> (LDP [32] src mem)) (Select1 <typ.UInt64> (LDP [32] src mem))
   485			(STP [16] dst (Select0 <typ.UInt64> (LDP [16] src mem)) (Select1 <typ.UInt64> (LDP [16] src mem))
   486				(STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem))))
   487
   488(MOVDstorezero {s} [i] ptr x:(MOVDstorezero {s} [i+8] ptr mem)) && x.Uses == 1 && setPos(v, x.Pos) && clobber(x) => (MOVQstorezero {s} [i] ptr mem)
   489(MOVDstorezero {s} [i] ptr x:(MOVDstorezero {s} [i-8] ptr mem)) && x.Uses == 1 && setPos(v, x.Pos) && clobber(x) => (MOVQstorezero {s} [i-8] ptr mem)
   490
   491// strip off fractional word move
   492(Move [s] dst src mem) && s%16 != 0 && s%16 <= 8 && s > 16 =>
   493	(Move [8]
   494		(OffPtr <dst.Type> dst [s-8])
   495		(OffPtr <src.Type> src [s-8])
   496		(Move [s-s%16] dst src mem))
   497(Move [s] dst src mem) && s%16 != 0 && s%16 > 8 && s > 16 =>
   498	(Move [16]
   499		(OffPtr <dst.Type> dst [s-16])
   500		(OffPtr <src.Type> src [s-16])
   501		(Move [s-s%16] dst src mem))
   502
   503// medium move uses a duff device
   504(Move [s] dst src mem)
   505	&& s > 64 && s <= 16*64 && s%16 == 0
   506	&& !config.noDuffDevice && logLargeCopy(v, s) =>
   507	(DUFFCOPY [8 * (64 - s/16)] dst src mem)
   508// 8 is the number of bytes to encode:
   509//
   510// LDP.P   16(R16), (R26, R27)
   511// STP.P   (R26, R27), 16(R17)
   512//
   513// 64 is number of these blocks. See runtime/duff_arm64.s:duffcopy
   514
   515// large move uses a loop
   516(Move [s] dst src mem)
   517	&& s%16 == 0 && (s > 16*64 || config.noDuffDevice)
   518	&& logLargeCopy(v, s) =>
   519	(LoweredMove
   520		dst
   521		src
   522		(ADDconst <src.Type> src [s-16])
   523		mem)
   524
   525// calls
   526(StaticCall  ...) => (CALLstatic  ...)
   527(ClosureCall ...) => (CALLclosure ...)
   528(InterCall   ...) => (CALLinter   ...)
   529(TailCall    ...) => (CALLtail    ...)
   530
   531// checks
   532(NilCheck ...) => (LoweredNilCheck ...)
   533(IsNonNil ptr) => (NotEqual (CMPconst [0] ptr))
   534(IsInBounds      idx len) => (LessThanU  (CMP idx len))
   535(IsSliceInBounds idx len) => (LessEqualU (CMP idx len))
   536
   537// pseudo-ops
   538(GetClosurePtr ...) => (LoweredGetClosurePtr ...)
   539(GetCallerSP   ...) => (LoweredGetCallerSP   ...)
   540(GetCallerPC   ...) => (LoweredGetCallerPC   ...)
   541
   542// Absorb pseudo-ops into blocks.
   543(If (Equal         cc) yes no) => (EQ cc yes no)
   544(If (NotEqual      cc) yes no) => (NE cc yes no)
   545(If (LessThan      cc) yes no) => (LT cc yes no)
   546(If (LessThanU     cc) yes no) => (ULT cc yes no)
   547(If (LessEqual     cc) yes no) => (LE cc yes no)
   548(If (LessEqualU    cc) yes no) => (ULE cc yes no)
   549(If (GreaterThan   cc) yes no) => (GT cc yes no)
   550(If (GreaterThanU  cc) yes no) => (UGT cc yes no)
   551(If (GreaterEqual  cc) yes no) => (GE cc yes no)
   552(If (GreaterEqualU cc) yes no) => (UGE cc yes no)
   553(If (LessThanF     cc) yes no) => (FLT cc yes no)
   554(If (LessEqualF    cc) yes no) => (FLE cc yes no)
   555(If (GreaterThanF  cc) yes no) => (FGT cc yes no)
   556(If (GreaterEqualF cc) yes no) => (FGE cc yes no)
   557
   558(If cond yes no) => (TBNZ [0] cond yes no)
   559
   560(JumpTable idx) => (JUMPTABLE {makeJumpTableSym(b)} idx (MOVDaddr <typ.Uintptr> {makeJumpTableSym(b)} (SB)))
   561
   562// atomic intrinsics
   563// Note: these ops do not accept offset.
   564(AtomicLoad8   ...) => (LDARB ...)
   565(AtomicLoad32  ...) => (LDARW ...)
   566(AtomicLoad64  ...) => (LDAR  ...)
   567(AtomicLoadPtr ...) => (LDAR  ...)
   568
   569(AtomicStore8       ...) => (STLRB ...)
   570(AtomicStore32      ...) => (STLRW ...)
   571(AtomicStore64      ...) => (STLR  ...)
   572(AtomicStorePtrNoWB ...) => (STLR  ...)
   573
   574(AtomicExchange(32|64)       ...) => (LoweredAtomicExchange(32|64) ...)
   575(AtomicAdd(32|64)            ...) => (LoweredAtomicAdd(32|64)      ...)
   576(AtomicCompareAndSwap(32|64) ...) => (LoweredAtomicCas(32|64)      ...)
   577
   578(AtomicAdd(32|64)Variant            ...) => (LoweredAtomicAdd(32|64)Variant      ...)
   579(AtomicExchange(32|64)Variant       ...) => (LoweredAtomicExchange(32|64)Variant ...)
   580(AtomicCompareAndSwap(32|64)Variant ...) => (LoweredAtomicCas(32|64)Variant      ...)
   581
   582// Return old contents.
   583(AtomicAnd(64|32|8)            ...) => (LoweredAtomicAnd(64|32|8)            ...)
   584(AtomicOr(64|32|8)             ...) => (LoweredAtomicOr(64|32|8)             ...)
   585(AtomicAnd(64|32|8)Variant     ...) => (LoweredAtomicAnd(64|32|8)Variant     ...)
   586(AtomicOr(64|32|8)Variant      ...) => (LoweredAtomicOr(64|32|8)Variant      ...)
   587
   588// Write barrier.
   589(WB ...) => (LoweredWB ...)
   590
   591// Publication barrier (0xe is ST option)
   592(PubBarrier mem) => (DMB [0xe] mem)
   593
   594(PanicBounds [kind] x y mem) && boundsABI(kind) == 0 => (LoweredPanicBoundsA [kind] x y mem)
   595(PanicBounds [kind] x y mem) && boundsABI(kind) == 1 => (LoweredPanicBoundsB [kind] x y mem)
   596(PanicBounds [kind] x y mem) && boundsABI(kind) == 2 => (LoweredPanicBoundsC [kind] x y mem)
   597
   598// Optimizations
   599
   600// Absorb boolean tests into block
   601(NZ (Equal         cc) yes no) => (EQ  cc yes no)
   602(NZ (NotEqual      cc) yes no) => (NE  cc yes no)
   603(NZ (LessThan      cc) yes no) => (LT  cc yes no)
   604(NZ (LessThanU     cc) yes no) => (ULT cc yes no)
   605(NZ (LessEqual     cc) yes no) => (LE  cc yes no)
   606(NZ (LessEqualU    cc) yes no) => (ULE cc yes no)
   607(NZ (GreaterThan   cc) yes no) => (GT  cc yes no)
   608(NZ (GreaterThanU  cc) yes no) => (UGT cc yes no)
   609(NZ (GreaterEqual  cc) yes no) => (GE  cc yes no)
   610(NZ (GreaterEqualU cc) yes no) => (UGE cc yes no)
   611(NZ (LessThanF     cc) yes no) => (FLT cc yes no)
   612(NZ (LessEqualF    cc) yes no) => (FLE cc yes no)
   613(NZ (GreaterThanF  cc) yes no) => (FGT cc yes no)
   614(NZ (GreaterEqualF cc) yes no) => (FGE cc yes no)
   615
   616(TBNZ [0] (Equal         cc) yes no) => (EQ  cc yes no)
   617(TBNZ [0] (NotEqual      cc) yes no) => (NE  cc yes no)
   618(TBNZ [0] (LessThan      cc) yes no) => (LT  cc yes no)
   619(TBNZ [0] (LessThanU     cc) yes no) => (ULT cc yes no)
   620(TBNZ [0] (LessEqual     cc) yes no) => (LE  cc yes no)
   621(TBNZ [0] (LessEqualU    cc) yes no) => (ULE cc yes no)
   622(TBNZ [0] (GreaterThan   cc) yes no) => (GT  cc yes no)
   623(TBNZ [0] (GreaterThanU  cc) yes no) => (UGT cc yes no)
   624(TBNZ [0] (GreaterEqual  cc) yes no) => (GE  cc yes no)
   625(TBNZ [0] (GreaterEqualU cc) yes no) => (UGE cc yes no)
   626(TBNZ [0] (LessThanF     cc) yes no) => (FLT cc yes no)
   627(TBNZ [0] (LessEqualF    cc) yes no) => (FLE cc yes no)
   628(TBNZ [0] (GreaterThanF  cc) yes no) => (FGT cc yes no)
   629(TBNZ [0] (GreaterEqualF cc) yes no) => (FGE cc yes no)
   630
   631((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] z:(AND        x y)) yes no) && z.Uses == 1 => ((EQ|NE|LT|LE|GT|GE) (TST                x y) yes no)
   632((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] x:(ANDconst [c] y)) yes no) && x.Uses == 1 => ((EQ|NE|LT|LE|GT|GE) (TSTconst         [c] y) yes no)
   633((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] z:(AND        x y)) yes no) && z.Uses == 1 => ((EQ|NE|LT|LE|GT|GE) (TSTW               x y) yes no)
   634((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] x:(ANDconst [c] y)) yes no) && x.Uses == 1 => ((EQ|NE|LT|LE|GT|GE) (TSTWconst [int32(c)] y) yes no)
   635
   636// For conditional instructions such as CSET, CSEL.
   637((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (CMPconst [0]  z:(AND        x y))) && z.Uses == 1 =>
   638	((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (TST x y))
   639((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (CMPWconst [0] x:(ANDconst [c] y))) && x.Uses == 1 =>
   640	((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (TSTWconst [int32(c)] y))
   641((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (CMPWconst [0] z:(AND        x y))) && z.Uses == 1 =>
   642	((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (TSTW x y))
   643((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (CMPconst [0]  x:(ANDconst [c] y))) && x.Uses == 1 =>
   644	((Equal|NotEqual|LessThan|LessEqual|GreaterThan|GreaterEqual) (TSTconst [c] y))
   645
   646((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] x:(ADDconst [c] y)) yes no) && x.Uses == 1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMNconst         [c] y) yes no)
   647((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] x:(ADDconst [c] y)) yes no) && x.Uses == 1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMNWconst [int32(c)] y) yes no)
   648((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] z:(ADD        x y)) yes no) && z.Uses == 1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMN                x y) yes no)
   649((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] z:(ADD        x y)) yes no) && z.Uses == 1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMNW               x y) yes no)
   650
   651// CMP(x,-y) -> CMN(x,y) is only valid for unordered comparison, if y can be -1<<63
   652((EQ|NE) (CMP x z:(NEG y)) yes no)   && z.Uses == 1 => ((EQ|NE) (CMN x y) yes no)
   653((Equal|NotEqual) (CMP x z:(NEG y))) && z.Uses == 1 => ((Equal|NotEqual) (CMN x y))
   654
   655// CMPW(x,-y) -> CMNW(x,y) is only valid for unordered comparison, if y can be -1<<31
   656((EQ|NE) (CMPW x z:(NEG y)) yes no)   && z.Uses == 1 => ((EQ|NE) (CMNW x y) yes no)
   657((Equal|NotEqual) (CMPW x z:(NEG y))) && z.Uses == 1 => ((Equal|NotEqual) (CMNW x y))
   658
   659// For conditional instructions such as CSET, CSEL.
   660// TODO: add support for LE, GT, overflow needs to be considered.
   661((Equal|NotEqual|LessThan|GreaterEqual) (CMPconst  [0] x:(ADDconst [c] y))) && x.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMNconst [c] y))
   662((Equal|NotEqual|LessThan|GreaterEqual) (CMPWconst [0] x:(ADDconst [c] y))) && x.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMNWconst [int32(c)] y))
   663((Equal|NotEqual|LessThan|GreaterEqual) (CMPconst  [0] z:(ADD        x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMN  x y))
   664((Equal|NotEqual|LessThan|GreaterEqual) (CMPWconst [0] z:(ADD        x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMNW x y))
   665((Equal|NotEqual|LessThan|GreaterEqual) (CMPconst  [0] z:(MADD     a x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMN  a (MUL  <x.Type> x y)))
   666((Equal|NotEqual|LessThan|GreaterEqual) (CMPconst  [0] z:(MSUB     a x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMP  a (MUL  <x.Type> x y)))
   667((Equal|NotEqual|LessThan|GreaterEqual) (CMPWconst [0] z:(MADDW    a x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMNW a (MULW <x.Type> x y)))
   668((Equal|NotEqual|LessThan|GreaterEqual) (CMPWconst [0] z:(MSUBW    a x y))) && z.Uses == 1 => ((Equal|NotEqual|LessThanNoov|GreaterEqualNoov) (CMPW a (MULW <x.Type> x y)))
   669
   670((CMPconst|CMNconst)   [c] y) && c < 0 && c != -1<<63 => ((CMNconst|CMPconst)   [-c] y)
   671((CMPWconst|CMNWconst) [c] y) && c < 0 && c != -1<<31 => ((CMNWconst|CMPWconst) [-c] y)
   672
   673((EQ|NE) (CMPconst  [0] x) yes no) => ((Z|NZ)   x yes no)
   674((EQ|NE) (CMPWconst [0] x) yes no) => ((ZW|NZW) x yes no)
   675
   676((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] z:(MADD a x y))  yes no) && z.Uses==1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMN  a (MUL  <x.Type> x y)) yes no)
   677((EQ|NE|LT|LE|GT|GE) (CMPconst  [0] z:(MSUB a x y))  yes no) && z.Uses==1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMP  a (MUL  <x.Type> x y)) yes no)
   678((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] z:(MADDW a x y)) yes no) && z.Uses==1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMNW a (MULW <x.Type> x y)) yes no)
   679((EQ|NE|LT|LE|GT|GE) (CMPWconst [0] z:(MSUBW a x y)) yes no) && z.Uses==1 => ((EQ|NE|LTnoov|LEnoov|GTnoov|GEnoov) (CMPW a (MULW <x.Type> x y)) yes no)
   680
   681// Absorb bit-tests into block
   682(Z   (ANDconst  [c] x) yes no) && oneBit(c) => (TBZ  [int64(ntz64(c))] x yes no)
   683(NZ  (ANDconst  [c] x) yes no) && oneBit(c) => (TBNZ [int64(ntz64(c))] x yes no)
   684(ZW  (ANDconst  [c] x) yes no) && oneBit(int64(uint32(c))) => (TBZ  [int64(ntz64(int64(uint32(c))))] x yes no)
   685(NZW (ANDconst  [c] x) yes no) && oneBit(int64(uint32(c))) => (TBNZ [int64(ntz64(int64(uint32(c))))] x yes no)
   686(EQ  (TSTconst  [c] x) yes no) && oneBit(c) => (TBZ  [int64(ntz64(c))] x yes no)
   687(NE  (TSTconst  [c] x) yes no) && oneBit(c) => (TBNZ [int64(ntz64(c))] x yes no)
   688(EQ  (TSTWconst [c] x) yes no) && oneBit(int64(uint32(c))) => (TBZ  [int64(ntz64(int64(uint32(c))))] x yes no)
   689(NE  (TSTWconst [c] x) yes no) && oneBit(int64(uint32(c))) => (TBNZ [int64(ntz64(int64(uint32(c))))] x yes no)
   690
   691// Test sign-bit for signed comparisons against zero
   692(GE (CMPWconst [0] x) yes no) => (TBZ  [31] x yes no)
   693(GE (CMPconst [0] x)  yes no) => (TBZ  [63] x yes no)
   694(LT (CMPWconst [0] x) yes no) => (TBNZ [31] x yes no)
   695(LT (CMPconst [0] x)  yes no) => (TBNZ [63] x yes no)
   696
   697// fold offset into address
   698(ADDconst [off1] (MOVDaddr [off2] {sym} ptr)) && is32Bit(off1+int64(off2)) =>
   699	 (MOVDaddr [int32(off1)+off2] {sym} ptr)
   700
   701// fold address into load/store.
   702// Do not fold global variable access in -dynlink mode, where it will
   703// be rewritten to use the GOT via REGTMP, which currently cannot handle
   704// large offset.
   705(MOVBload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   706	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   707	(MOVBload [off1+int32(off2)] {sym} ptr mem)
   708(MOVBUload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   709	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   710	(MOVBUload [off1+int32(off2)] {sym} ptr mem)
   711(MOVHload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   712	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   713	(MOVHload [off1+int32(off2)] {sym} ptr mem)
   714(MOVHUload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   715	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   716	(MOVHUload [off1+int32(off2)] {sym} ptr mem)
   717(MOVWload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   718	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   719	(MOVWload [off1+int32(off2)] {sym} ptr mem)
   720(MOVWUload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   721	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   722	(MOVWUload [off1+int32(off2)] {sym} ptr mem)
   723(MOVDload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   724	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   725	(MOVDload [off1+int32(off2)] {sym} ptr mem)
   726(LDP [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   727	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   728	(LDP [off1+int32(off2)] {sym} ptr mem)
   729(FMOVSload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   730	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   731	(FMOVSload [off1+int32(off2)] {sym} ptr mem)
   732(FMOVDload [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   733	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   734	(FMOVDload [off1+int32(off2)] {sym} ptr mem)
   735
   736// register indexed load
   737(MOVDload  [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVDloadidx ptr idx mem)
   738(MOVWUload [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVWUloadidx ptr idx mem)
   739(MOVWload  [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVWloadidx ptr idx mem)
   740(MOVHUload [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVHUloadidx ptr idx mem)
   741(MOVHload  [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVHloadidx ptr idx mem)
   742(MOVBUload [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVBUloadidx ptr idx mem)
   743(MOVBload  [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVBloadidx ptr idx mem)
   744(FMOVSload [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (FMOVSloadidx ptr idx mem)
   745(FMOVDload [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (FMOVDloadidx ptr idx mem)
   746
   747(MOVDloadidx  ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVDload  [int32(c)] ptr mem)
   748(MOVDloadidx  (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVDload  [int32(c)] ptr mem)
   749(MOVWUloadidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVWUload [int32(c)] ptr mem)
   750(MOVWUloadidx (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVWUload [int32(c)] ptr mem)
   751(MOVWloadidx  ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVWload  [int32(c)] ptr mem)
   752(MOVWloadidx  (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVWload  [int32(c)] ptr mem)
   753(MOVHUloadidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVHUload [int32(c)] ptr mem)
   754(MOVHUloadidx (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVHUload [int32(c)] ptr mem)
   755(MOVHloadidx  ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVHload  [int32(c)] ptr mem)
   756(MOVHloadidx  (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVHload  [int32(c)] ptr mem)
   757(MOVBUloadidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVBUload [int32(c)] ptr mem)
   758(MOVBUloadidx (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVBUload [int32(c)] ptr mem)
   759(MOVBloadidx  ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVBload  [int32(c)] ptr mem)
   760(MOVBloadidx  (MOVDconst [c]) ptr mem) && is32Bit(c) => (MOVBload  [int32(c)] ptr mem)
   761(FMOVSloadidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (FMOVSload [int32(c)] ptr mem)
   762(FMOVSloadidx (MOVDconst [c]) ptr mem) && is32Bit(c) => (FMOVSload [int32(c)] ptr mem)
   763(FMOVDloadidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (FMOVDload [int32(c)] ptr mem)
   764(FMOVDloadidx (MOVDconst [c]) ptr mem) && is32Bit(c) => (FMOVDload [int32(c)] ptr mem)
   765
   766// shifted register indexed load
   767(MOVDload  [off] {sym} (ADDshiftLL [3] ptr idx) mem) && off == 0 && sym == nil => (MOVDloadidx8 ptr idx mem)
   768(MOVWUload [off] {sym} (ADDshiftLL [2] ptr idx) mem) && off == 0 && sym == nil => (MOVWUloadidx4 ptr idx mem)
   769(MOVWload  [off] {sym} (ADDshiftLL [2] ptr idx) mem) && off == 0 && sym == nil => (MOVWloadidx4 ptr idx mem)
   770(MOVHUload [off] {sym} (ADDshiftLL [1] ptr idx) mem) && off == 0 && sym == nil => (MOVHUloadidx2 ptr idx mem)
   771(MOVHload  [off] {sym} (ADDshiftLL [1] ptr idx) mem) && off == 0 && sym == nil => (MOVHloadidx2 ptr idx mem)
   772(MOVDloadidx  ptr (SLLconst [3] idx) mem) => (MOVDloadidx8 ptr idx mem)
   773(MOVWloadidx  ptr (SLLconst [2] idx) mem) => (MOVWloadidx4 ptr idx mem)
   774(MOVWUloadidx ptr (SLLconst [2] idx) mem) => (MOVWUloadidx4 ptr idx mem)
   775(MOVHloadidx  ptr (SLLconst [1] idx) mem) => (MOVHloadidx2 ptr idx mem)
   776(MOVHUloadidx ptr (SLLconst [1] idx) mem) => (MOVHUloadidx2 ptr idx mem)
   777(MOVHloadidx  ptr (ADD idx idx) mem) => (MOVHloadidx2 ptr idx mem)
   778(MOVHUloadidx ptr (ADD idx idx) mem) => (MOVHUloadidx2 ptr idx mem)
   779(MOVDloadidx  (SLLconst [3] idx) ptr mem) => (MOVDloadidx8 ptr idx mem)
   780(MOVWloadidx  (SLLconst [2] idx) ptr mem) => (MOVWloadidx4 ptr idx mem)
   781(MOVWUloadidx (SLLconst [2] idx) ptr mem) => (MOVWUloadidx4 ptr idx mem)
   782(MOVHloadidx  (ADD idx idx) ptr mem) => (MOVHloadidx2 ptr idx mem)
   783(MOVHUloadidx (ADD idx idx) ptr mem) => (MOVHUloadidx2 ptr idx mem)
   784(MOVDloadidx8  ptr (MOVDconst [c]) mem) && is32Bit(c<<3) => (MOVDload  [int32(c)<<3] ptr mem)
   785(MOVWUloadidx4 ptr (MOVDconst [c]) mem) && is32Bit(c<<2) => (MOVWUload [int32(c)<<2] ptr mem)
   786(MOVWloadidx4  ptr (MOVDconst [c]) mem) && is32Bit(c<<2) => (MOVWload  [int32(c)<<2] ptr mem)
   787(MOVHUloadidx2 ptr (MOVDconst [c]) mem) && is32Bit(c<<1) => (MOVHUload [int32(c)<<1] ptr mem)
   788(MOVHloadidx2  ptr (MOVDconst [c]) mem) && is32Bit(c<<1) => (MOVHload  [int32(c)<<1] ptr mem)
   789
   790(FMOVDload [off] {sym} (ADDshiftLL [3] ptr idx) mem) && off == 0 && sym == nil => (FMOVDloadidx8 ptr idx mem)
   791(FMOVSload [off] {sym} (ADDshiftLL [2] ptr idx) mem) && off == 0 && sym == nil => (FMOVSloadidx4 ptr idx mem)
   792(FMOVDloadidx ptr (SLLconst [3] idx) mem) => (FMOVDloadidx8 ptr idx mem)
   793(FMOVSloadidx ptr (SLLconst [2] idx) mem) => (FMOVSloadidx4 ptr idx mem)
   794(FMOVDloadidx (SLLconst [3] idx) ptr mem) => (FMOVDloadidx8 ptr idx mem)
   795(FMOVSloadidx (SLLconst [2] idx) ptr mem) => (FMOVSloadidx4 ptr idx mem)
   796(FMOVDloadidx8 ptr (MOVDconst [c]) mem) && is32Bit(c<<3) => (FMOVDload ptr [int32(c)<<3] mem)
   797(FMOVSloadidx4 ptr (MOVDconst [c]) mem) && is32Bit(c<<2) => (FMOVSload ptr [int32(c)<<2] mem)
   798
   799(MOVBstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   800	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   801	(MOVBstore [off1+int32(off2)] {sym} ptr val mem)
   802(MOVHstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   803	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   804	(MOVHstore [off1+int32(off2)] {sym} ptr val mem)
   805(MOVWstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   806	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   807	(MOVWstore [off1+int32(off2)] {sym} ptr val mem)
   808(MOVDstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   809	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   810	(MOVDstore [off1+int32(off2)] {sym} ptr val mem)
   811(STP [off1] {sym} (ADDconst [off2] ptr) val1 val2 mem) && is32Bit(int64(off1)+off2)
   812	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   813	(STP [off1+int32(off2)] {sym} ptr val1 val2 mem)
   814(FMOVSstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   815	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   816	(FMOVSstore [off1+int32(off2)] {sym} ptr val mem)
   817(FMOVDstore [off1] {sym} (ADDconst [off2] ptr) val mem) && is32Bit(int64(off1)+off2)
   818	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   819	(FMOVDstore [off1+int32(off2)] {sym} ptr val mem)
   820(MOVBstorezero [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   821	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   822	(MOVBstorezero [off1+int32(off2)] {sym} ptr mem)
   823(MOVHstorezero [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   824	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   825	(MOVHstorezero [off1+int32(off2)] {sym} ptr mem)
   826(MOVWstorezero [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   827	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   828	(MOVWstorezero [off1+int32(off2)] {sym} ptr mem)
   829(MOVDstorezero [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   830	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   831	(MOVDstorezero [off1+int32(off2)] {sym} ptr mem)
   832(MOVQstorezero [off1] {sym} (ADDconst [off2] ptr) mem) && is32Bit(int64(off1)+off2)
   833	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   834	(MOVQstorezero [off1+int32(off2)] {sym} ptr mem)
   835
   836// register indexed store
   837(MOVDstore  [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (MOVDstoreidx ptr idx val mem)
   838(MOVWstore  [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (MOVWstoreidx ptr idx val mem)
   839(MOVHstore  [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (MOVHstoreidx ptr idx val mem)
   840(MOVBstore  [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (MOVBstoreidx ptr idx val mem)
   841(FMOVDstore [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (FMOVDstoreidx ptr idx val mem)
   842(FMOVSstore [off] {sym} (ADD ptr idx) val mem) && off == 0 && sym == nil => (FMOVSstoreidx ptr idx val mem)
   843(MOVDstoreidx  ptr (MOVDconst [c]) val mem) && is32Bit(c) => (MOVDstore  [int32(c)] ptr val mem)
   844(MOVDstoreidx  (MOVDconst [c]) idx val mem) && is32Bit(c) => (MOVDstore  [int32(c)] idx val mem)
   845(MOVWstoreidx  ptr (MOVDconst [c]) val mem) && is32Bit(c) => (MOVWstore  [int32(c)] ptr val mem)
   846(MOVWstoreidx  (MOVDconst [c]) idx val mem) && is32Bit(c) => (MOVWstore  [int32(c)] idx val mem)
   847(MOVHstoreidx  ptr (MOVDconst [c]) val mem) && is32Bit(c) => (MOVHstore  [int32(c)] ptr val mem)
   848(MOVHstoreidx  (MOVDconst [c]) idx val mem) && is32Bit(c) => (MOVHstore  [int32(c)] idx val mem)
   849(MOVBstoreidx  ptr (MOVDconst [c]) val mem) && is32Bit(c) => (MOVBstore  [int32(c)] ptr val mem)
   850(MOVBstoreidx  (MOVDconst [c]) idx val mem) && is32Bit(c) => (MOVBstore  [int32(c)] idx val mem)
   851(FMOVDstoreidx ptr (MOVDconst [c]) val mem) && is32Bit(c) => (FMOVDstore [int32(c)] ptr val mem)
   852(FMOVDstoreidx (MOVDconst [c]) idx val mem) && is32Bit(c) => (FMOVDstore [int32(c)] idx val mem)
   853(FMOVSstoreidx ptr (MOVDconst [c]) val mem) && is32Bit(c) => (FMOVSstore [int32(c)] ptr val mem)
   854(FMOVSstoreidx (MOVDconst [c]) idx val mem) && is32Bit(c) => (FMOVSstore [int32(c)] idx val mem)
   855
   856// shifted register indexed store
   857(MOVDstore [off] {sym} (ADDshiftLL [3] ptr idx) val mem) && off == 0 && sym == nil => (MOVDstoreidx8 ptr idx val mem)
   858(MOVWstore [off] {sym} (ADDshiftLL [2] ptr idx) val mem) && off == 0 && sym == nil => (MOVWstoreidx4 ptr idx val mem)
   859(MOVHstore [off] {sym} (ADDshiftLL [1] ptr idx) val mem) && off == 0 && sym == nil => (MOVHstoreidx2 ptr idx val mem)
   860(MOVDstoreidx  ptr (SLLconst [3] idx) val mem) => (MOVDstoreidx8 ptr idx val mem)
   861(MOVWstoreidx  ptr (SLLconst [2] idx) val mem) => (MOVWstoreidx4 ptr idx val mem)
   862(MOVHstoreidx  ptr (SLLconst [1] idx) val mem) => (MOVHstoreidx2 ptr idx val mem)
   863(MOVHstoreidx  ptr (ADD      idx idx) val mem) => (MOVHstoreidx2 ptr idx val mem)
   864(MOVDstoreidx  (SLLconst [3] idx) ptr val mem) => (MOVDstoreidx8 ptr idx val mem)
   865(MOVWstoreidx  (SLLconst [2] idx) ptr val mem) => (MOVWstoreidx4 ptr idx val mem)
   866(MOVHstoreidx  (SLLconst [1] idx) ptr val mem) => (MOVHstoreidx2 ptr idx val mem)
   867(MOVHstoreidx  (ADD      idx idx) ptr val mem) => (MOVHstoreidx2 ptr idx val mem)
   868(MOVDstoreidx8 ptr (MOVDconst [c]) val mem) && is32Bit(c<<3) => (MOVDstore [int32(c)<<3] ptr val mem)
   869(MOVWstoreidx4 ptr (MOVDconst [c]) val mem) && is32Bit(c<<2) => (MOVWstore [int32(c)<<2] ptr val mem)
   870(MOVHstoreidx2 ptr (MOVDconst [c]) val mem) && is32Bit(c<<1) => (MOVHstore [int32(c)<<1] ptr val mem)
   871
   872(FMOVDstore [off] {sym} (ADDshiftLL [3] ptr idx) val mem) && off == 0 && sym == nil => (FMOVDstoreidx8 ptr idx val mem)
   873(FMOVSstore [off] {sym} (ADDshiftLL [2] ptr idx) val mem) && off == 0 && sym == nil => (FMOVSstoreidx4 ptr idx val mem)
   874(FMOVDstoreidx ptr (SLLconst [3] idx) val mem) => (FMOVDstoreidx8 ptr idx val mem)
   875(FMOVSstoreidx ptr (SLLconst [2] idx) val mem) => (FMOVSstoreidx4 ptr idx val mem)
   876(FMOVDstoreidx (SLLconst [3] idx) ptr val mem) => (FMOVDstoreidx8 ptr idx val mem)
   877(FMOVSstoreidx (SLLconst [2] idx) ptr val mem) => (FMOVSstoreidx4 ptr idx val mem)
   878(FMOVDstoreidx8 ptr (MOVDconst [c]) val mem) && is32Bit(c<<3) => (FMOVDstore [int32(c)<<3] ptr val mem)
   879(FMOVSstoreidx4 ptr (MOVDconst [c]) val mem) && is32Bit(c<<2) => (FMOVSstore [int32(c)<<2] ptr val mem)
   880
   881(MOVBload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   882	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   883	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   884	(MOVBload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   885(MOVBUload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   886	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   887	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   888	(MOVBUload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   889(MOVHload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   890	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   891	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   892	(MOVHload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   893(MOVHUload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   894	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   895	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   896	(MOVHUload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   897(MOVWload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   898	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   899	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   900	(MOVWload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   901(MOVWUload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   902	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   903	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   904	(MOVWUload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   905(MOVDload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   906	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   907	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   908	(MOVDload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   909(LDP [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   910	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   911	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   912	(LDP [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   913(FMOVSload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   914	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   915	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   916	(FMOVSload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   917(FMOVDload [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   918	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   919	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   920	(FMOVDload [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   921
   922(MOVBstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   923	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   924	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   925	(MOVBstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   926(MOVHstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   927	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   928	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   929	(MOVHstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   930(MOVWstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   931	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   932	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   933	(MOVWstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   934(MOVDstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   935	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   936	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   937	(MOVDstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   938(STP [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val1 val2 mem)
   939	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   940	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   941	(STP [off1+off2] {mergeSym(sym1,sym2)} ptr val1 val2 mem)
   942(FMOVSstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   943	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   944	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   945	(FMOVSstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   946(FMOVDstore [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) val mem)
   947	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   948	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   949	(FMOVDstore [off1+off2] {mergeSym(sym1,sym2)} ptr val mem)
   950(MOVBstorezero [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   951	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   952	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   953	(MOVBstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   954(MOVHstorezero [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   955	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   956	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   957	(MOVHstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   958(MOVWstorezero [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   959	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   960	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   961	(MOVWstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   962(MOVDstorezero [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   963	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   964	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   965	(MOVDstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   966(MOVQstorezero [off1] {sym1} (MOVDaddr [off2] {sym2} ptr) mem)
   967	&& canMergeSym(sym1,sym2) && is32Bit(int64(off1)+int64(off2))
   968	&& (ptr.Op != OpSB || !config.ctxt.Flag_dynlink) =>
   969	(MOVQstorezero [off1+off2] {mergeSym(sym1,sym2)} ptr mem)
   970
   971// store zero
   972(MOVBstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVBstorezero [off] {sym} ptr mem)
   973(MOVHstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVHstorezero [off] {sym} ptr mem)
   974(MOVWstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVWstorezero [off] {sym} ptr mem)
   975(MOVDstore [off] {sym} ptr (MOVDconst [0]) mem) => (MOVDstorezero [off] {sym} ptr mem)
   976(STP [off] {sym} ptr (MOVDconst [0]) (MOVDconst [0]) mem) => (MOVQstorezero [off] {sym} ptr mem)
   977
   978// register indexed store zero
   979(MOVDstorezero [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVDstorezeroidx ptr idx mem)
   980(MOVWstorezero [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVWstorezeroidx ptr idx mem)
   981(MOVHstorezero [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVHstorezeroidx ptr idx mem)
   982(MOVBstorezero [off] {sym} (ADD ptr idx) mem) && off == 0 && sym == nil => (MOVBstorezeroidx ptr idx mem)
   983(MOVDstoreidx ptr idx (MOVDconst [0]) mem) => (MOVDstorezeroidx ptr idx mem)
   984(MOVWstoreidx ptr idx (MOVDconst [0]) mem) => (MOVWstorezeroidx ptr idx mem)
   985(MOVHstoreidx ptr idx (MOVDconst [0]) mem) => (MOVHstorezeroidx ptr idx mem)
   986(MOVBstoreidx ptr idx (MOVDconst [0]) mem) => (MOVBstorezeroidx ptr idx mem)
   987(MOVDstorezeroidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVDstorezero [int32(c)] ptr mem)
   988(MOVDstorezeroidx (MOVDconst [c]) idx mem) && is32Bit(c) => (MOVDstorezero [int32(c)] idx mem)
   989(MOVWstorezeroidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVWstorezero [int32(c)] ptr mem)
   990(MOVWstorezeroidx (MOVDconst [c]) idx mem) && is32Bit(c) => (MOVWstorezero [int32(c)] idx mem)
   991(MOVHstorezeroidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVHstorezero [int32(c)] ptr mem)
   992(MOVHstorezeroidx (MOVDconst [c]) idx mem) && is32Bit(c) => (MOVHstorezero [int32(c)] idx mem)
   993(MOVBstorezeroidx ptr (MOVDconst [c]) mem) && is32Bit(c) => (MOVBstorezero [int32(c)] ptr mem)
   994(MOVBstorezeroidx (MOVDconst [c]) idx mem) && is32Bit(c) => (MOVBstorezero [int32(c)] idx mem)
   995
   996// shifted register indexed store zero
   997(MOVDstorezero [off] {sym} (ADDshiftLL [3] ptr idx) mem) && off == 0 && sym == nil => (MOVDstorezeroidx8 ptr idx mem)
   998(MOVWstorezero [off] {sym} (ADDshiftLL [2] ptr idx) mem) && off == 0 && sym == nil => (MOVWstorezeroidx4 ptr idx mem)
   999(MOVHstorezero [off] {sym} (ADDshiftLL [1] ptr idx) mem) && off == 0 && sym == nil => (MOVHstorezeroidx2 ptr idx mem)
  1000(MOVDstorezeroidx ptr (SLLconst [3] idx) mem) => (MOVDstorezeroidx8 ptr idx mem)
  1001(MOVWstorezeroidx ptr (SLLconst [2] idx) mem) => (MOVWstorezeroidx4 ptr idx mem)
  1002(MOVHstorezeroidx ptr (SLLconst [1] idx) mem) => (MOVHstorezeroidx2 ptr idx mem)
  1003(MOVHstorezeroidx ptr (ADD      idx idx) mem) => (MOVHstorezeroidx2 ptr idx mem)
  1004(MOVDstorezeroidx (SLLconst [3] idx) ptr mem) => (MOVDstorezeroidx8 ptr idx mem)
  1005(MOVWstorezeroidx (SLLconst [2] idx) ptr mem) => (MOVWstorezeroidx4 ptr idx mem)
  1006(MOVHstorezeroidx (SLLconst [1] idx) ptr mem) => (MOVHstorezeroidx2 ptr idx mem)
  1007(MOVHstorezeroidx (ADD      idx idx) ptr mem) => (MOVHstorezeroidx2 ptr idx mem)
  1008(MOVDstoreidx8 ptr idx (MOVDconst [0]) mem) => (MOVDstorezeroidx8 ptr idx mem)
  1009(MOVWstoreidx4 ptr idx (MOVDconst [0]) mem) => (MOVWstorezeroidx4 ptr idx mem)
  1010(MOVHstoreidx2 ptr idx (MOVDconst [0]) mem) => (MOVHstorezeroidx2 ptr idx mem)
  1011(MOVDstorezeroidx8 ptr (MOVDconst [c]) mem) && is32Bit(c<<3) => (MOVDstorezero [int32(c<<3)] ptr mem)
  1012(MOVWstorezeroidx4 ptr (MOVDconst [c]) mem) && is32Bit(c<<2) => (MOVWstorezero [int32(c<<2)] ptr mem)
  1013(MOVHstorezeroidx2 ptr (MOVDconst [c]) mem) && is32Bit(c<<1) => (MOVHstorezero [int32(c<<1)] ptr mem)
  1014
  1015// replace load from same location as preceding store with zero/sign extension (or copy in case of full width)
  1016// these seem to have bad interaction with other rules, resulting in slower code
  1017//(MOVBload  [off] {sym} ptr (MOVBstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVBreg x)
  1018//(MOVBUload [off] {sym} ptr (MOVBstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVBUreg x)
  1019//(MOVHload  [off] {sym} ptr (MOVHstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVHreg x)
  1020//(MOVHUload [off] {sym} ptr (MOVHstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVHUreg x)
  1021//(MOVWload  [off] {sym} ptr (MOVWstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVWreg x)
  1022//(MOVWUload [off] {sym} ptr (MOVWstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> (MOVWUreg x)
  1023//(MOVDload  [off] {sym} ptr (MOVDstore  [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> x
  1024//(FMOVSload [off] {sym} ptr (FMOVSstore [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> x
  1025//(FMOVDload [off] {sym} ptr (FMOVDstore [off2] {sym2} ptr2 x _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> x
  1026//(LDP       [off] {sym} ptr (STP      [off2] {sym2} ptr2 x y _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) -> x y
  1027
  1028(MOVBload  [off] {sym} ptr (MOVBstorezero [off2] {sym2} ptr2 _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => (MOVDconst [0])
  1029(MOVBUload [off] {sym} ptr (MOVBstorezero [off2] {sym2} ptr2 _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => (MOVDconst [0])
  1030(MOVHload  [off] {sym} ptr (MOVHstorezero [off2] {sym2} ptr2 _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => (MOVDconst [0])
  1031(MOVHUload [off] {sym} ptr (MOVHstorezero [off2] {sym2} ptr2 _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => (MOVDconst [0])
  1032(MOVWload  [off] {sym} ptr (MOVWstorezero [off2] {sym2} ptr2 _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => (MOVDconst [0])
  1033(MOVWUload [off] {sym} ptr (MOVWstorezero [off2] {sym2} ptr2 _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => (MOVDconst [0])
  1034(MOVDload  [off] {sym} ptr (MOVDstorezero [off2] {sym2} ptr2 _)) && sym == sym2 && off == off2 && isSamePtr(ptr, ptr2) => (MOVDconst [0])
  1035
  1036(MOVBloadidx ptr idx (MOVBstorezeroidx ptr2 idx2 _))
  1037	&& (isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) || isSamePtr(ptr, idx2) && isSamePtr(idx, ptr2)) => (MOVDconst [0])
  1038(MOVBUloadidx ptr idx (MOVBstorezeroidx ptr2 idx2 _))
  1039	&& (isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) || isSamePtr(ptr, idx2) && isSamePtr(idx, ptr2)) => (MOVDconst [0])
  1040(MOVHloadidx ptr idx (MOVHstorezeroidx ptr2 idx2 _))
  1041	&& (isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) || isSamePtr(ptr, idx2) && isSamePtr(idx, ptr2)) => (MOVDconst [0])
  1042(MOVHUloadidx ptr idx (MOVHstorezeroidx ptr2 idx2 _))
  1043	&& (isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) || isSamePtr(ptr, idx2) && isSamePtr(idx, ptr2)) => (MOVDconst [0])
  1044(MOVWloadidx ptr idx (MOVWstorezeroidx ptr2 idx2 _))
  1045	&& (isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) || isSamePtr(ptr, idx2) && isSamePtr(idx, ptr2)) => (MOVDconst [0])
  1046(MOVWUloadidx ptr idx (MOVWstorezeroidx ptr2 idx2 _))
  1047	&& (isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) || isSamePtr(ptr, idx2) && isSamePtr(idx, ptr2)) => (MOVDconst [0])
  1048(MOVDloadidx ptr idx (MOVDstorezeroidx ptr2 idx2 _))
  1049	&& (isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) || isSamePtr(ptr, idx2) && isSamePtr(idx, ptr2)) => (MOVDconst [0])
  1050
  1051(MOVHloadidx2  ptr idx (MOVHstorezeroidx2 ptr2 idx2 _)) && isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) => (MOVDconst [0])
  1052(MOVHUloadidx2 ptr idx (MOVHstorezeroidx2 ptr2 idx2 _)) && isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) => (MOVDconst [0])
  1053(MOVWloadidx4  ptr idx (MOVWstorezeroidx4 ptr2 idx2 _)) && isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) => (MOVDconst [0])
  1054(MOVWUloadidx4 ptr idx (MOVWstorezeroidx4 ptr2 idx2 _)) && isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) => (MOVDconst [0])
  1055(MOVDloadidx8  ptr idx (MOVDstorezeroidx8 ptr2 idx2 _)) && isSamePtr(ptr, ptr2) && isSamePtr(idx, idx2) => (MOVDconst [0])
  1056
  1057// don't extend before store
  1058(MOVBstore [off] {sym} ptr (MOVBreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
  1059(MOVBstore [off] {sym} ptr (MOVBUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
  1060(MOVBstore [off] {sym} ptr (MOVHreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
  1061(MOVBstore [off] {sym} ptr (MOVHUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
  1062(MOVBstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVBstore [off] {sym} ptr x mem)
  1063(MOVBstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVBstore [off] {sym} ptr x mem)
  1064(MOVHstore [off] {sym} ptr (MOVHreg  x) mem) => (MOVHstore [off] {sym} ptr x mem)
  1065(MOVHstore [off] {sym} ptr (MOVHUreg x) mem) => (MOVHstore [off] {sym} ptr x mem)
  1066(MOVHstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVHstore [off] {sym} ptr x mem)
  1067(MOVHstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVHstore [off] {sym} ptr x mem)
  1068(MOVWstore [off] {sym} ptr (MOVWreg  x) mem) => (MOVWstore [off] {sym} ptr x mem)
  1069(MOVWstore [off] {sym} ptr (MOVWUreg x) mem) => (MOVWstore [off] {sym} ptr x mem)
  1070(MOVBstoreidx  ptr idx (MOVBreg  x) mem) => (MOVBstoreidx  ptr idx x mem)
  1071(MOVBstoreidx  ptr idx (MOVBUreg x) mem) => (MOVBstoreidx  ptr idx x mem)
  1072(MOVBstoreidx  ptr idx (MOVHreg  x) mem) => (MOVBstoreidx  ptr idx x mem)
  1073(MOVBstoreidx  ptr idx (MOVHUreg x) mem) => (MOVBstoreidx  ptr idx x mem)
  1074(MOVBstoreidx  ptr idx (MOVWreg  x) mem) => (MOVBstoreidx  ptr idx x mem)
  1075(MOVBstoreidx  ptr idx (MOVWUreg x) mem) => (MOVBstoreidx  ptr idx x mem)
  1076(MOVHstoreidx  ptr idx (MOVHreg  x) mem) => (MOVHstoreidx  ptr idx x mem)
  1077(MOVHstoreidx  ptr idx (MOVHUreg x) mem) => (MOVHstoreidx  ptr idx x mem)
  1078(MOVHstoreidx  ptr idx (MOVWreg  x) mem) => (MOVHstoreidx  ptr idx x mem)
  1079(MOVHstoreidx  ptr idx (MOVWUreg x) mem) => (MOVHstoreidx  ptr idx x mem)
  1080(MOVWstoreidx  ptr idx (MOVWreg  x) mem) => (MOVWstoreidx  ptr idx x mem)
  1081(MOVWstoreidx  ptr idx (MOVWUreg x) mem) => (MOVWstoreidx  ptr idx x mem)
  1082(MOVHstoreidx2 ptr idx (MOVHreg  x) mem) => (MOVHstoreidx2 ptr idx x mem)
  1083(MOVHstoreidx2 ptr idx (MOVHUreg x) mem) => (MOVHstoreidx2 ptr idx x mem)
  1084(MOVHstoreidx2 ptr idx (MOVWreg  x) mem) => (MOVHstoreidx2 ptr idx x mem)
  1085(MOVHstoreidx2 ptr idx (MOVWUreg x) mem) => (MOVHstoreidx2 ptr idx x mem)
  1086(MOVWstoreidx4 ptr idx (MOVWreg  x) mem) => (MOVWstoreidx4 ptr idx x mem)
  1087(MOVWstoreidx4 ptr idx (MOVWUreg x) mem) => (MOVWstoreidx4 ptr idx x mem)
  1088
  1089// if a register move has only 1 use, just use the same register without emitting instruction
  1090// MOVDnop doesn't emit instruction, only for ensuring the type.
  1091(MOVDreg x) && x.Uses == 1 => (MOVDnop x)
  1092
  1093// TODO: we should be able to get rid of MOVDnop all together.
  1094// But for now, this is enough to get rid of lots of them.
  1095(MOVDnop (MOVDconst [c])) => (MOVDconst [c])
  1096
  1097// fold constant into arithmetic ops
  1098(ADD  x (MOVDconst <t> [c])) && !t.IsPtr() => (ADDconst [c] x)
  1099(SUB  x (MOVDconst [c])) => (SUBconst [c] x)
  1100(AND  x (MOVDconst [c])) => (ANDconst [c] x)
  1101(OR   x (MOVDconst [c])) => (ORconst  [c] x)
  1102(XOR  x (MOVDconst [c])) => (XORconst [c] x)
  1103(TST  x (MOVDconst [c])) => (TSTconst [c] x)
  1104(TSTW x (MOVDconst [c])) => (TSTWconst [int32(c)] x)
  1105(CMN  x (MOVDconst [c])) => (CMNconst [c] x)
  1106(CMNW x (MOVDconst [c])) => (CMNWconst [int32(c)] x)
  1107(BIC  x (MOVDconst [c])) => (ANDconst [^c] x)
  1108(EON  x (MOVDconst [c])) => (XORconst [^c] x)
  1109(ORN  x (MOVDconst [c])) => (ORconst  [^c] x)
  1110
  1111(SLL x (MOVDconst [c])) => (SLLconst x [c&63])
  1112(SRL x (MOVDconst [c])) => (SRLconst x [c&63])
  1113(SRA x (MOVDconst [c])) => (SRAconst x [c&63])
  1114(SLL x (ANDconst [63] y)) => (SLL x y)
  1115(SRL x (ANDconst [63] y)) => (SRL x y)
  1116(SRA x (ANDconst [63] y)) => (SRA x y)
  1117
  1118(CMP  x (MOVDconst [c])) => (CMPconst [c] x)
  1119(CMP  (MOVDconst [c]) x) => (InvertFlags (CMPconst [c] x))
  1120(CMPW x (MOVDconst [c])) => (CMPWconst [int32(c)] x)
  1121(CMPW (MOVDconst [c]) x) => (InvertFlags (CMPWconst [int32(c)] x))
  1122
  1123(ROR  x (MOVDconst [c])) => (RORconst x [c&63])
  1124(RORW x (MOVDconst [c])) => (RORWconst x [c&31])
  1125
  1126(ADDSflags x (MOVDconst [c]))  => (ADDSconstflags [c] x)
  1127
  1128(ADDconst [c] y) && c < 0 => (SUBconst [-c] y)
  1129
  1130// Canonicalize the order of arguments to comparisons - helps with CSE.
  1131((CMP|CMPW) x y) && canonLessThan(x,y) => (InvertFlags ((CMP|CMPW) y x))
  1132
  1133// mul-neg => mneg
  1134(NEG  (MUL  x y)) => (MNEG  x y)
  1135(NEG  (MULW x y)) && v.Type.Size() <= 4 => (MNEGW x y)
  1136(MUL  (NEG  x) y) => (MNEG  x y)
  1137(MULW (NEG  x) y) => (MNEGW x y)
  1138
  1139// madd/msub
  1140(ADD a l:(MUL  x y)) && l.Uses==1 && clobber(l) => (MADD a x y)
  1141(SUB a l:(MUL  x y)) && l.Uses==1 && clobber(l) => (MSUB a x y)
  1142(ADD a l:(MNEG x y)) && l.Uses==1 && clobber(l) => (MSUB a x y)
  1143(SUB a l:(MNEG x y)) && l.Uses==1 && clobber(l) => (MADD a x y)
  1144
  1145(ADD a l:(MULW  x y)) && v.Type.Size() <= 4 && l.Uses==1 && clobber(l) => (MADDW a x y)
  1146(SUB a l:(MULW  x y)) && v.Type.Size() <= 4 && l.Uses==1 && clobber(l) => (MSUBW a x y)
  1147(ADD a l:(MNEGW x y)) && v.Type.Size() <= 4 && l.Uses==1 && clobber(l) => (MSUBW a x y)
  1148(SUB a l:(MNEGW x y)) && v.Type.Size() <= 4 && l.Uses==1 && clobber(l) => (MADDW a x y)
  1149
  1150// optimize ADCSflags, SBCSflags and friends
  1151(ADCSflags x y (Select1 <types.TypeFlags> (ADDSconstflags [-1] (ADCzerocarry <typ.UInt64> c)))) => (ADCSflags x y c)
  1152(ADCSflags x y (Select1 <types.TypeFlags> (ADDSconstflags [-1] (MOVDconst [0])))) => (ADDSflags x y)
  1153(SBCSflags x y (Select1 <types.TypeFlags> (NEGSflags (NEG <typ.UInt64> (NGCzerocarry <typ.UInt64> bo))))) => (SBCSflags x y bo)
  1154(SBCSflags x y (Select1 <types.TypeFlags> (NEGSflags (MOVDconst [0])))) => (SUBSflags x y)
  1155
  1156// mul by constant
  1157(MUL x (MOVDconst [-1])) => (NEG x)
  1158(MUL _ (MOVDconst [0])) => (MOVDconst [0])
  1159(MUL x (MOVDconst [1])) => x
  1160(MUL x (MOVDconst [c])) && isPowerOfTwo64(c) => (SLLconst [log64(c)] x)
  1161(MUL x (MOVDconst [c])) && isPowerOfTwo64(c-1) && c >= 3 => (ADDshiftLL x x [log64(c-1)])
  1162(MUL x (MOVDconst [c])) && isPowerOfTwo64(c+1) && c >= 7 => (ADDshiftLL (NEG <x.Type> x) x [log64(c+1)])
  1163(MUL x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo64(c/3) => (SLLconst [log64(c/3)] (ADDshiftLL <x.Type> x x [1]))
  1164(MUL x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo64(c/5) => (SLLconst [log64(c/5)] (ADDshiftLL <x.Type> x x [2]))
  1165(MUL x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo64(c/7) => (SLLconst [log64(c/7)] (ADDshiftLL <x.Type> (NEG <x.Type> x) x [3]))
  1166(MUL x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo64(c/9) => (SLLconst [log64(c/9)] (ADDshiftLL <x.Type> x x [3]))
  1167
  1168(MULW x (MOVDconst [c])) && int32(c)==-1 => (MOVWUreg (NEG <x.Type> x))
  1169(MULW _ (MOVDconst [c])) && int32(c)==0 => (MOVDconst [0])
  1170(MULW x (MOVDconst [c])) && int32(c)==1 => (MOVWUreg x)
  1171(MULW x (MOVDconst [c])) && isPowerOfTwo64(c) => (MOVWUreg (SLLconst <x.Type> [log64(c)] x))
  1172(MULW x (MOVDconst [c])) && isPowerOfTwo64(c-1) && int32(c) >= 3 => (MOVWUreg (ADDshiftLL <x.Type> x x [log64(c-1)]))
  1173(MULW x (MOVDconst [c])) && isPowerOfTwo64(c+1) && int32(c) >= 7 => (MOVWUreg (ADDshiftLL <x.Type> (NEG <x.Type> x) x [log64(c+1)]))
  1174(MULW x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo64(c/3) && is32Bit(c) => (MOVWUreg (SLLconst <x.Type> [log64(c/3)] (ADDshiftLL <x.Type> x x [1])))
  1175(MULW x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo64(c/5) && is32Bit(c) => (MOVWUreg (SLLconst <x.Type> [log64(c/5)] (ADDshiftLL <x.Type> x x [2])))
  1176(MULW x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo64(c/7) && is32Bit(c) => (MOVWUreg (SLLconst <x.Type> [log64(c/7)] (ADDshiftLL <x.Type> (NEG <x.Type> x) x [3])))
  1177(MULW x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo64(c/9) && is32Bit(c) => (MOVWUreg (SLLconst <x.Type> [log64(c/9)] (ADDshiftLL <x.Type> x x [3])))
  1178
  1179// mneg by constant
  1180(MNEG x (MOVDconst [-1])) => x
  1181(MNEG _ (MOVDconst [0])) => (MOVDconst [0])
  1182(MNEG x (MOVDconst [1])) => (NEG x)
  1183(MNEG x (MOVDconst [c])) && isPowerOfTwo64(c) => (NEG (SLLconst <x.Type> [log64(c)] x))
  1184(MNEG x (MOVDconst [c])) && isPowerOfTwo64(c-1) && c >= 3 => (NEG (ADDshiftLL <x.Type> x x [log64(c-1)]))
  1185(MNEG x (MOVDconst [c])) && isPowerOfTwo64(c+1) && c >= 7 => (NEG (ADDshiftLL <x.Type> (NEG <x.Type> x) x [log64(c+1)]))
  1186(MNEG x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo64(c/3) => (SLLconst <x.Type> [log64(c/3)] (SUBshiftLL <x.Type> x x [2]))
  1187(MNEG x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo64(c/5) => (NEG (SLLconst <x.Type> [log64(c/5)] (ADDshiftLL <x.Type> x x [2])))
  1188(MNEG x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo64(c/7) => (SLLconst <x.Type> [log64(c/7)] (SUBshiftLL <x.Type> x x [3]))
  1189(MNEG x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo64(c/9) => (NEG (SLLconst <x.Type> [log64(c/9)] (ADDshiftLL <x.Type> x x [3])))
  1190
  1191
  1192(MNEGW x (MOVDconst [c])) && int32(c)==-1 => (MOVWUreg x)
  1193(MNEGW _ (MOVDconst [c])) && int32(c)==0 => (MOVDconst [0])
  1194(MNEGW x (MOVDconst [c])) && int32(c)==1 => (MOVWUreg (NEG <x.Type> x))
  1195(MNEGW x (MOVDconst [c])) && isPowerOfTwo64(c) => (NEG (SLLconst <x.Type> [log64(c)] x))
  1196(MNEGW x (MOVDconst [c])) && isPowerOfTwo64(c-1) && int32(c) >= 3 => (MOVWUreg (NEG <x.Type> (ADDshiftLL <x.Type> x x [log64(c-1)])))
  1197(MNEGW x (MOVDconst [c])) && isPowerOfTwo64(c+1) && int32(c) >= 7 => (MOVWUreg (NEG <x.Type> (ADDshiftLL <x.Type> (NEG <x.Type> x) x [log64(c+1)])))
  1198(MNEGW x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo64(c/3) && is32Bit(c) => (MOVWUreg (SLLconst <x.Type> [log64(c/3)] (SUBshiftLL <x.Type> x x [2])))
  1199(MNEGW x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo64(c/5) && is32Bit(c) => (MOVWUreg (NEG <x.Type> (SLLconst <x.Type> [log64(c/5)] (ADDshiftLL <x.Type> x x [2]))))
  1200(MNEGW x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo64(c/7) && is32Bit(c) => (MOVWUreg (SLLconst <x.Type> [log64(c/7)] (SUBshiftLL <x.Type> x x [3])))
  1201(MNEGW x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo64(c/9) && is32Bit(c) => (MOVWUreg (NEG <x.Type> (SLLconst <x.Type> [log64(c/9)] (ADDshiftLL <x.Type> x x [3]))))
  1202
  1203
  1204(MADD a x (MOVDconst [-1])) => (SUB a x)
  1205(MADD a _ (MOVDconst [0])) => a
  1206(MADD a x (MOVDconst [1])) => (ADD a x)
  1207(MADD a x (MOVDconst [c])) && isPowerOfTwo64(c) => (ADDshiftLL a x [log64(c)])
  1208(MADD a x (MOVDconst [c])) && isPowerOfTwo64(c-1) && c>=3 => (ADD a (ADDshiftLL <x.Type> x x [log64(c-1)]))
  1209(MADD a x (MOVDconst [c])) && isPowerOfTwo64(c+1) && c>=7 => (SUB a (SUBshiftLL <x.Type> x x [log64(c+1)]))
  1210(MADD a x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo64(c/3) => (SUBshiftLL a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)])
  1211(MADD a x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo64(c/5) => (ADDshiftLL a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)])
  1212(MADD a x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo64(c/7) => (SUBshiftLL a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)])
  1213(MADD a x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo64(c/9) => (ADDshiftLL a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)])
  1214
  1215(MADD a (MOVDconst [-1]) x) => (SUB a x)
  1216(MADD a (MOVDconst [0]) _) => a
  1217(MADD a (MOVDconst [1]) x) => (ADD a x)
  1218(MADD a (MOVDconst [c]) x) && isPowerOfTwo64(c) => (ADDshiftLL a x [log64(c)])
  1219(MADD a (MOVDconst [c]) x) && isPowerOfTwo64(c-1) && c>=3 => (ADD a (ADDshiftLL <x.Type> x x [log64(c-1)]))
  1220(MADD a (MOVDconst [c]) x) && isPowerOfTwo64(c+1) && c>=7 => (SUB a (SUBshiftLL <x.Type> x x [log64(c+1)]))
  1221(MADD a (MOVDconst [c]) x) && c%3 == 0 && isPowerOfTwo64(c/3) => (SUBshiftLL a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)])
  1222(MADD a (MOVDconst [c]) x) && c%5 == 0 && isPowerOfTwo64(c/5) => (ADDshiftLL a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)])
  1223(MADD a (MOVDconst [c]) x) && c%7 == 0 && isPowerOfTwo64(c/7) => (SUBshiftLL a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)])
  1224(MADD a (MOVDconst [c]) x) && c%9 == 0 && isPowerOfTwo64(c/9) => (ADDshiftLL a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)])
  1225
  1226(MADDW a x (MOVDconst [c])) && int32(c)==-1 => (MOVWUreg (SUB <a.Type> a x))
  1227(MADDW a _ (MOVDconst [c])) && int32(c)==0 => (MOVWUreg a)
  1228(MADDW a x (MOVDconst [c])) && int32(c)==1 => (MOVWUreg (ADD <a.Type> a x))
  1229(MADDW a x (MOVDconst [c])) && isPowerOfTwo64(c) => (MOVWUreg (ADDshiftLL <a.Type> a x [log64(c)]))
  1230(MADDW a x (MOVDconst [c])) && isPowerOfTwo64(c-1) && int32(c)>=3 => (MOVWUreg (ADD <a.Type> a (ADDshiftLL <x.Type> x x [log64(c-1)])))
  1231(MADDW a x (MOVDconst [c])) && isPowerOfTwo64(c+1) && int32(c)>=7 => (MOVWUreg (SUB <a.Type> a (SUBshiftLL <x.Type> x x [log64(c+1)])))
  1232(MADDW a x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo64(c/3) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)]))
  1233(MADDW a x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo64(c/5) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)]))
  1234(MADDW a x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo64(c/7) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)]))
  1235(MADDW a x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo64(c/9) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)]))
  1236
  1237(MADDW a (MOVDconst [c]) x) && int32(c)==-1 => (MOVWUreg (SUB <a.Type> a x))
  1238(MADDW a (MOVDconst [c]) _) && int32(c)==0 => (MOVWUreg a)
  1239(MADDW a (MOVDconst [c]) x) && int32(c)==1 => (MOVWUreg (ADD <a.Type> a x))
  1240(MADDW a (MOVDconst [c]) x) && isPowerOfTwo64(c) => (MOVWUreg (ADDshiftLL <a.Type> a x [log64(c)]))
  1241(MADDW a (MOVDconst [c]) x) && isPowerOfTwo64(c-1) && int32(c)>=3 => (MOVWUreg (ADD <a.Type> a (ADDshiftLL <x.Type> x x [log64(c-1)])))
  1242(MADDW a (MOVDconst [c]) x) && isPowerOfTwo64(c+1) && int32(c)>=7 => (MOVWUreg (SUB <a.Type> a (SUBshiftLL <x.Type> x x [log64(c+1)])))
  1243(MADDW a (MOVDconst [c]) x) && c%3 == 0 && isPowerOfTwo64(c/3) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)]))
  1244(MADDW a (MOVDconst [c]) x) && c%5 == 0 && isPowerOfTwo64(c/5) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)]))
  1245(MADDW a (MOVDconst [c]) x) && c%7 == 0 && isPowerOfTwo64(c/7) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)]))
  1246(MADDW a (MOVDconst [c]) x) && c%9 == 0 && isPowerOfTwo64(c/9) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)]))
  1247
  1248(MSUB a x (MOVDconst [-1])) => (ADD a x)
  1249(MSUB a _ (MOVDconst [0])) => a
  1250(MSUB a x (MOVDconst [1])) => (SUB a x)
  1251(MSUB a x (MOVDconst [c])) && isPowerOfTwo64(c) => (SUBshiftLL a x [log64(c)])
  1252(MSUB a x (MOVDconst [c])) && isPowerOfTwo64(c-1) && c>=3 => (SUB a (ADDshiftLL <x.Type> x x [log64(c-1)]))
  1253(MSUB a x (MOVDconst [c])) && isPowerOfTwo64(c+1) && c>=7 => (ADD a (SUBshiftLL <x.Type> x x [log64(c+1)]))
  1254(MSUB a x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo64(c/3) => (ADDshiftLL a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)])
  1255(MSUB a x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo64(c/5) => (SUBshiftLL a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)])
  1256(MSUB a x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo64(c/7) => (ADDshiftLL a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)])
  1257(MSUB a x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo64(c/9) => (SUBshiftLL a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)])
  1258
  1259(MSUB a (MOVDconst [-1]) x) => (ADD a x)
  1260(MSUB a (MOVDconst [0]) _) => a
  1261(MSUB a (MOVDconst [1]) x) => (SUB a x)
  1262(MSUB a (MOVDconst [c]) x) && isPowerOfTwo64(c) => (SUBshiftLL a x [log64(c)])
  1263(MSUB a (MOVDconst [c]) x) && isPowerOfTwo64(c-1) && c>=3 => (SUB a (ADDshiftLL <x.Type> x x [log64(c-1)]))
  1264(MSUB a (MOVDconst [c]) x) && isPowerOfTwo64(c+1) && c>=7 => (ADD a (SUBshiftLL <x.Type> x x [log64(c+1)]))
  1265(MSUB a (MOVDconst [c]) x) && c%3 == 0 && isPowerOfTwo64(c/3) => (ADDshiftLL a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)])
  1266(MSUB a (MOVDconst [c]) x) && c%5 == 0 && isPowerOfTwo64(c/5) => (SUBshiftLL a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)])
  1267(MSUB a (MOVDconst [c]) x) && c%7 == 0 && isPowerOfTwo64(c/7) => (ADDshiftLL a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)])
  1268(MSUB a (MOVDconst [c]) x) && c%9 == 0 && isPowerOfTwo64(c/9) => (SUBshiftLL a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)])
  1269
  1270(MSUBW a x (MOVDconst [c])) && int32(c)==-1 => (MOVWUreg (ADD <a.Type> a x))
  1271(MSUBW a _ (MOVDconst [c])) && int32(c)==0 => (MOVWUreg a)
  1272(MSUBW a x (MOVDconst [c])) && int32(c)==1 => (MOVWUreg (SUB <a.Type> a x))
  1273(MSUBW a x (MOVDconst [c])) && isPowerOfTwo64(c) => (MOVWUreg (SUBshiftLL <a.Type> a x [log64(c)]))
  1274(MSUBW a x (MOVDconst [c])) && isPowerOfTwo64(c-1) && int32(c)>=3 => (MOVWUreg (SUB <a.Type> a (ADDshiftLL <x.Type> x x [log64(c-1)])))
  1275(MSUBW a x (MOVDconst [c])) && isPowerOfTwo64(c+1) && int32(c)>=7 => (MOVWUreg (ADD <a.Type> a (SUBshiftLL <x.Type> x x [log64(c+1)])))
  1276(MSUBW a x (MOVDconst [c])) && c%3 == 0 && isPowerOfTwo64(c/3) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)]))
  1277(MSUBW a x (MOVDconst [c])) && c%5 == 0 && isPowerOfTwo64(c/5) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)]))
  1278(MSUBW a x (MOVDconst [c])) && c%7 == 0 && isPowerOfTwo64(c/7) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)]))
  1279(MSUBW a x (MOVDconst [c])) && c%9 == 0 && isPowerOfTwo64(c/9) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)]))
  1280
  1281(MSUBW a (MOVDconst [c]) x) && int32(c)==-1 => (MOVWUreg (ADD <a.Type> a x))
  1282(MSUBW a (MOVDconst [c]) _) && int32(c)==0 => (MOVWUreg a)
  1283(MSUBW a (MOVDconst [c]) x) && int32(c)==1 => (MOVWUreg (SUB <a.Type> a x))
  1284(MSUBW a (MOVDconst [c]) x) && isPowerOfTwo64(c) => (MOVWUreg (SUBshiftLL <a.Type> a x [log64(c)]))
  1285(MSUBW a (MOVDconst [c]) x) && isPowerOfTwo64(c-1) && int32(c)>=3 => (MOVWUreg (SUB <a.Type> a (ADDshiftLL <x.Type> x x [log64(c-1)])))
  1286(MSUBW a (MOVDconst [c]) x) && isPowerOfTwo64(c+1) && int32(c)>=7 => (MOVWUreg (ADD <a.Type> a (SUBshiftLL <x.Type> x x [log64(c+1)])))
  1287(MSUBW a (MOVDconst [c]) x) && c%3 == 0 && isPowerOfTwo64(c/3) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [2]) [log64(c/3)]))
  1288(MSUBW a (MOVDconst [c]) x) && c%5 == 0 && isPowerOfTwo64(c/5) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [2]) [log64(c/5)]))
  1289(MSUBW a (MOVDconst [c]) x) && c%7 == 0 && isPowerOfTwo64(c/7) && is32Bit(c) => (MOVWUreg (ADDshiftLL <a.Type> a (SUBshiftLL <x.Type> x x [3]) [log64(c/7)]))
  1290(MSUBW a (MOVDconst [c]) x) && c%9 == 0 && isPowerOfTwo64(c/9) && is32Bit(c) => (MOVWUreg (SUBshiftLL <a.Type> a (ADDshiftLL <x.Type> x x [3]) [log64(c/9)]))
  1291
  1292// div by constant
  1293(UDIV  x (MOVDconst [1])) => x
  1294(UDIV  x (MOVDconst [c])) && isPowerOfTwo64(c) => (SRLconst [log64(c)] x)
  1295(UDIVW x (MOVDconst [c])) && uint32(c)==1 => (MOVWUreg x)
  1296(UDIVW x (MOVDconst [c])) && isPowerOfTwo64(c) && is32Bit(c) => (SRLconst [log64(c)] (MOVWUreg <v.Type> x))
  1297(UMOD  _ (MOVDconst [1])) => (MOVDconst [0])
  1298(UMOD  x (MOVDconst [c])) && isPowerOfTwo64(c) => (ANDconst [c-1] x)
  1299(UMODW _ (MOVDconst [c])) && uint32(c)==1 => (MOVDconst [0])
  1300(UMODW x (MOVDconst [c])) && isPowerOfTwo64(c) && is32Bit(c) => (ANDconst [c-1] x)
  1301
  1302// generic simplifications
  1303(ADD x (NEG y)) => (SUB x y)
  1304(SUB x x) => (MOVDconst [0])
  1305(AND x x) => x
  1306(OR  x x) => x
  1307(XOR x x) => (MOVDconst [0])
  1308(BIC x x) => (MOVDconst [0])
  1309(EON x x) => (MOVDconst [-1])
  1310(ORN x x) => (MOVDconst [-1])
  1311(AND x (MVN y)) => (BIC x y)
  1312(XOR x (MVN y)) => (EON x y)
  1313(OR  x (MVN y)) => (ORN x y)
  1314(MVN (XOR x y)) => (EON x y)
  1315(NEG (NEG x)) => x
  1316
  1317(CSEL [cc] (MOVDconst [-1]) (MOVDconst [0]) flag) => (CSETM [cc] flag)
  1318(CSEL [cc] (MOVDconst [0]) (MOVDconst [-1]) flag) => (CSETM [arm64Negate(cc)] flag)
  1319(CSEL [cc] x (MOVDconst [0]) flag) => (CSEL0 [cc] x flag)
  1320(CSEL [cc] (MOVDconst [0]) y flag) => (CSEL0 [arm64Negate(cc)] y flag)
  1321(CSEL [cc] x (ADDconst [1] a) flag) => (CSINC [cc] x a flag)
  1322(CSEL [cc] (ADDconst [1] a) x flag) => (CSINC [arm64Negate(cc)] x a flag)
  1323(CSEL [cc] x (MVN a) flag) => (CSINV [cc] x a flag)
  1324(CSEL [cc] (MVN a) x flag) => (CSINV [arm64Negate(cc)] x a flag)
  1325(CSEL [cc] x (NEG a) flag) => (CSNEG [cc] x a flag)
  1326(CSEL [cc] (NEG a) x flag) => (CSNEG [arm64Negate(cc)] x a flag)
  1327
  1328(SUB x (SUB y z)) => (SUB (ADD <v.Type> x z) y)
  1329(SUB (SUB x y) z) => (SUB x (ADD <y.Type> y z))
  1330
  1331// remove redundant *const ops
  1332(ADDconst [0]  x) => x
  1333(SUBconst [0]  x) => x
  1334(ANDconst [0]  _) => (MOVDconst [0])
  1335(ANDconst [-1] x) => x
  1336(ORconst  [0]  x) => x
  1337(ORconst  [-1] _) => (MOVDconst [-1])
  1338(XORconst [0]  x) => x
  1339(XORconst [-1] x) => (MVN x)
  1340
  1341// generic constant folding
  1342(ADDconst [c] (MOVDconst [d]))  => (MOVDconst [c+d])
  1343(ADDconst [c] (ADDconst [d] x)) => (ADDconst [c+d] x)
  1344(ADDconst [c] (SUBconst [d] x)) => (ADDconst [c-d] x)
  1345(SUBconst [c] (MOVDconst [d]))  => (MOVDconst [d-c])
  1346(SUBconst [c] (SUBconst [d] x)) => (ADDconst [-c-d] x)
  1347(SUBconst [c] (ADDconst [d] x)) => (ADDconst [-c+d] x)
  1348(SLLconst [c] (MOVDconst [d]))  => (MOVDconst [d<<uint64(c)])
  1349(SRLconst [c] (MOVDconst [d]))  => (MOVDconst [int64(uint64(d)>>uint64(c))])
  1350(SRAconst [c] (MOVDconst [d]))  => (MOVDconst [d>>uint64(c)])
  1351(MUL   (MOVDconst [c]) (MOVDconst [d])) => (MOVDconst [c*d])
  1352(MNEG  (MOVDconst [c]) (MOVDconst [d])) => (MOVDconst [-c*d])
  1353(MULW  (MOVDconst [c]) (MOVDconst [d])) => (MOVDconst [int64(uint32(c*d))])
  1354(MNEGW (MOVDconst [c]) (MOVDconst [d])) => (MOVDconst [int64(uint32(-c*d))])
  1355(MADD  (MOVDconst [c]) x y) => (ADDconst [c] (MUL  <x.Type> x y))
  1356(MSUB  (MOVDconst [c]) x y) => (ADDconst [c] (MNEG <x.Type> x y))
  1357(MADD  a (MOVDconst [c]) (MOVDconst [d])) => (ADDconst [c*d] a)
  1358(MSUB  a (MOVDconst [c]) (MOVDconst [d])) => (SUBconst [c*d] a)
  1359(MADDW (MOVDconst [c]) x y) => (MOVWUreg (ADDconst <x.Type> [c] (MULW  <x.Type> x y)))
  1360(MSUBW (MOVDconst [c]) x y) => (MOVWUreg (ADDconst <x.Type> [c] (MNEGW <x.Type> x y)))
  1361(MADDW a (MOVDconst [c]) (MOVDconst [d])) => (MOVWUreg (ADDconst <a.Type> [c*d] a))
  1362(MSUBW a (MOVDconst [c]) (MOVDconst [d])) => (MOVWUreg (SUBconst <a.Type> [c*d] a))
  1363(DIV   (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [c/d])
  1364(UDIV  (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint64(c)/uint64(d))])
  1365(DIVW  (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint32(int32(c)/int32(d)))])
  1366(UDIVW (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint32(c)/uint32(d))])
  1367(MOD   (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [c%d])
  1368(UMOD  (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint64(c)%uint64(d))])
  1369(MODW  (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint32(int32(c)%int32(d)))])
  1370(UMODW (MOVDconst [c]) (MOVDconst [d])) && d != 0 => (MOVDconst [int64(uint32(c)%uint32(d))])
  1371(ANDconst [c] (MOVDconst [d]))  => (MOVDconst [c&d])
  1372(ANDconst [c] (ANDconst [d] x)) => (ANDconst [c&d] x)
  1373(ANDconst [c] (MOVWUreg x)) => (ANDconst [c&(1<<32-1)] x)
  1374(ANDconst [c] (MOVHUreg x)) => (ANDconst [c&(1<<16-1)] x)
  1375(ANDconst [c] (MOVBUreg x)) => (ANDconst [c&(1<<8-1)] x)
  1376(MOVWUreg (ANDconst [c] x)) => (ANDconst [c&(1<<32-1)] x)
  1377(MOVHUreg (ANDconst [c] x)) => (ANDconst [c&(1<<16-1)] x)
  1378(MOVBUreg (ANDconst [c] x)) => (ANDconst [c&(1<<8-1)] x)
  1379(ORconst  [c] (MOVDconst [d]))  => (MOVDconst [c|d])
  1380(ORconst  [c] (ORconst [d] x))  => (ORconst [c|d] x)
  1381(XORconst [c] (MOVDconst [d]))  => (MOVDconst [c^d])
  1382(XORconst [c] (XORconst [d] x)) => (XORconst [c^d] x)
  1383(MVN (MOVDconst [c])) => (MOVDconst [^c])
  1384(NEG (MOVDconst [c])) => (MOVDconst [-c])
  1385(MOVBreg  (MOVDconst [c])) => (MOVDconst [int64(int8(c))])
  1386(MOVBUreg (MOVDconst [c])) => (MOVDconst [int64(uint8(c))])
  1387(MOVHreg  (MOVDconst [c])) => (MOVDconst [int64(int16(c))])
  1388(MOVHUreg (MOVDconst [c])) => (MOVDconst [int64(uint16(c))])
  1389(MOVWreg  (MOVDconst [c])) => (MOVDconst [int64(int32(c))])
  1390(MOVWUreg (MOVDconst [c])) => (MOVDconst [int64(uint32(c))])
  1391(MOVDreg  (MOVDconst [c])) => (MOVDconst [c])
  1392
  1393// constant comparisons
  1394(CMPconst  (MOVDconst [x]) [y]) => (FlagConstant [subFlags64(x,y)])
  1395(CMPWconst (MOVDconst [x]) [y]) => (FlagConstant [subFlags32(int32(x),y)])
  1396(TSTconst  (MOVDconst [x]) [y]) => (FlagConstant [logicFlags64(x&y)])
  1397(TSTWconst (MOVDconst [x]) [y]) => (FlagConstant [logicFlags32(int32(x)&y)])
  1398(CMNconst  (MOVDconst [x]) [y]) => (FlagConstant [addFlags64(x,y)])
  1399(CMNWconst (MOVDconst [x]) [y]) => (FlagConstant [addFlags32(int32(x),y)])
  1400
  1401// other known comparisons
  1402(CMPconst  (MOVBUreg _) [c]) && 0xff < c       => (FlagConstant [subFlags64(0,1)])
  1403(CMPconst  (MOVHUreg _) [c]) && 0xffff < c     => (FlagConstant [subFlags64(0,1)])
  1404(CMPconst  (MOVWUreg _) [c]) && 0xffffffff < c => (FlagConstant [subFlags64(0,1)])
  1405(CMPconst  (ANDconst _ [m]) [n]) && 0 <= m && m < n => (FlagConstant [subFlags64(0,1)])
  1406(CMPconst  (SRLconst _ [c]) [n]) && 0 <= n && 0 < c && c <= 63 && (1<<uint64(64-c)) <= uint64(n) => (FlagConstant [subFlags64(0,1)])
  1407(CMPWconst (MOVBUreg _) [c]) && 0xff   < c => (FlagConstant [subFlags64(0,1)])
  1408(CMPWconst (MOVHUreg _) [c]) && 0xffff < c => (FlagConstant [subFlags64(0,1)])
  1409
  1410// absorb flag constants into branches
  1411(EQ (FlagConstant [fc]) yes no) &&  fc.eq() => (First yes no)
  1412(EQ (FlagConstant [fc]) yes no) && !fc.eq() => (First no yes)
  1413
  1414(NE (FlagConstant [fc]) yes no) &&  fc.ne() => (First yes no)
  1415(NE (FlagConstant [fc]) yes no) && !fc.ne() => (First no yes)
  1416
  1417(LT (FlagConstant [fc]) yes no) &&  fc.lt() => (First yes no)
  1418(LT (FlagConstant [fc]) yes no) && !fc.lt() => (First no yes)
  1419
  1420(LE (FlagConstant [fc]) yes no) &&  fc.le() => (First yes no)
  1421(LE (FlagConstant [fc]) yes no) && !fc.le() => (First no yes)
  1422
  1423(GT (FlagConstant [fc]) yes no) &&  fc.gt() => (First yes no)
  1424(GT (FlagConstant [fc]) yes no) && !fc.gt() => (First no yes)
  1425
  1426(GE (FlagConstant [fc]) yes no) &&  fc.ge() => (First yes no)
  1427(GE (FlagConstant [fc]) yes no) && !fc.ge() => (First no yes)
  1428
  1429(ULT (FlagConstant [fc]) yes no) &&  fc.ult() => (First yes no)
  1430(ULT (FlagConstant [fc]) yes no) && !fc.ult() => (First no yes)
  1431
  1432(ULE (FlagConstant [fc]) yes no) &&  fc.ule() => (First yes no)
  1433(ULE (FlagConstant [fc]) yes no) && !fc.ule() => (First no yes)
  1434
  1435(UGT (FlagConstant [fc]) yes no) &&  fc.ugt() => (First yes no)
  1436(UGT (FlagConstant [fc]) yes no) && !fc.ugt() => (First no yes)
  1437
  1438(UGE (FlagConstant [fc]) yes no) &&  fc.uge() => (First yes no)
  1439(UGE (FlagConstant [fc]) yes no) && !fc.uge() => (First no yes)
  1440
  1441(LTnoov (FlagConstant [fc]) yes no) &&  fc.ltNoov() => (First yes no)
  1442(LTnoov (FlagConstant [fc]) yes no) && !fc.ltNoov() => (First no yes)
  1443
  1444(LEnoov (FlagConstant [fc]) yes no) &&  fc.leNoov() => (First yes no)
  1445(LEnoov (FlagConstant [fc]) yes no) && !fc.leNoov() => (First no yes)
  1446
  1447(GTnoov (FlagConstant [fc]) yes no) &&  fc.gtNoov() => (First yes no)
  1448(GTnoov (FlagConstant [fc]) yes no) && !fc.gtNoov() => (First no yes)
  1449
  1450(GEnoov (FlagConstant [fc]) yes no) &&  fc.geNoov() => (First yes no)
  1451(GEnoov (FlagConstant [fc]) yes no) && !fc.geNoov() => (First no yes)
  1452
  1453(Z   (MOVDconst [0]) yes no)                  => (First yes no)
  1454(Z   (MOVDconst [c]) yes no) && c != 0        => (First no yes)
  1455(NZ  (MOVDconst [0]) yes no)                  => (First no yes)
  1456(NZ  (MOVDconst [c]) yes no) && c != 0        => (First yes no)
  1457(ZW  (MOVDconst [c]) yes no) && int32(c) == 0 => (First yes no)
  1458(ZW  (MOVDconst [c]) yes no) && int32(c) != 0 => (First no yes)
  1459(NZW (MOVDconst [c]) yes no) && int32(c) == 0 => (First no yes)
  1460(NZW (MOVDconst [c]) yes no) && int32(c) != 0 => (First yes no)
  1461
  1462// absorb InvertFlags into branches
  1463(LT  (InvertFlags cmp) yes no) => (GT cmp yes no)
  1464(GT  (InvertFlags cmp) yes no) => (LT cmp yes no)
  1465(LE  (InvertFlags cmp) yes no) => (GE cmp yes no)
  1466(GE  (InvertFlags cmp) yes no) => (LE cmp yes no)
  1467(ULT (InvertFlags cmp) yes no) => (UGT cmp yes no)
  1468(UGT (InvertFlags cmp) yes no) => (ULT cmp yes no)
  1469(ULE (InvertFlags cmp) yes no) => (UGE cmp yes no)
  1470(UGE (InvertFlags cmp) yes no) => (ULE cmp yes no)
  1471(EQ  (InvertFlags cmp) yes no) => (EQ cmp yes no)
  1472(NE  (InvertFlags cmp) yes no) => (NE cmp yes no)
  1473(FLT (InvertFlags cmp) yes no) => (FGT cmp yes no)
  1474(FGT (InvertFlags cmp) yes no) => (FLT cmp yes no)
  1475(FLE (InvertFlags cmp) yes no) => (FGE cmp yes no)
  1476(FGE (InvertFlags cmp) yes no) => (FLE cmp yes no)
  1477(LTnoov (InvertFlags cmp) yes no) => (GTnoov cmp yes no)
  1478(GEnoov (InvertFlags cmp) yes no) => (LEnoov cmp yes no)
  1479(LEnoov (InvertFlags cmp) yes no) => (GEnoov cmp yes no)
  1480(GTnoov (InvertFlags cmp) yes no) => (LTnoov cmp yes no)
  1481
  1482// absorb InvertFlags into conditional instructions
  1483(CSEL  [cc] x y (InvertFlags cmp)) => (CSEL  [arm64Invert(cc)] x y cmp)
  1484(CSEL0 [cc] x   (InvertFlags cmp)) => (CSEL0 [arm64Invert(cc)] x   cmp)
  1485(CSETM [cc]     (InvertFlags cmp)) => (CSETM [arm64Invert(cc)]     cmp)
  1486(CSINC [cc] x y (InvertFlags cmp)) => (CSINC [arm64Invert(cc)] x y cmp)
  1487(CSINV [cc] x y (InvertFlags cmp)) => (CSINV [arm64Invert(cc)] x y cmp)
  1488(CSNEG [cc] x y (InvertFlags cmp)) => (CSNEG [arm64Invert(cc)] x y cmp)
  1489
  1490// absorb flag constants into boolean values
  1491(Equal         (FlagConstant [fc])) => (MOVDconst [b2i(fc.eq())])
  1492(NotEqual      (FlagConstant [fc])) => (MOVDconst [b2i(fc.ne())])
  1493(LessThan      (FlagConstant [fc])) => (MOVDconst [b2i(fc.lt())])
  1494(LessThanU     (FlagConstant [fc])) => (MOVDconst [b2i(fc.ult())])
  1495(LessEqual     (FlagConstant [fc])) => (MOVDconst [b2i(fc.le())])
  1496(LessEqualU    (FlagConstant [fc])) => (MOVDconst [b2i(fc.ule())])
  1497(GreaterThan   (FlagConstant [fc])) => (MOVDconst [b2i(fc.gt())])
  1498(GreaterThanU  (FlagConstant [fc])) => (MOVDconst [b2i(fc.ugt())])
  1499(GreaterEqual  (FlagConstant [fc])) => (MOVDconst [b2i(fc.ge())])
  1500(GreaterEqualU (FlagConstant [fc])) => (MOVDconst [b2i(fc.uge())])
  1501
  1502// absorb InvertFlags into boolean values
  1503(Equal            (InvertFlags x)) => (Equal x)
  1504(NotEqual         (InvertFlags x)) => (NotEqual x)
  1505(LessThan         (InvertFlags x)) => (GreaterThan x)
  1506(LessThanU        (InvertFlags x)) => (GreaterThanU x)
  1507(GreaterThan      (InvertFlags x)) => (LessThan x)
  1508(GreaterThanU     (InvertFlags x)) => (LessThanU x)
  1509(LessEqual        (InvertFlags x)) => (GreaterEqual x)
  1510(LessEqualU       (InvertFlags x)) => (GreaterEqualU x)
  1511(GreaterEqual     (InvertFlags x)) => (LessEqual x)
  1512(GreaterEqualU    (InvertFlags x)) => (LessEqualU x)
  1513(LessThanF        (InvertFlags x)) => (GreaterThanF x)
  1514(LessEqualF       (InvertFlags x)) => (GreaterEqualF x)
  1515(GreaterThanF     (InvertFlags x)) => (LessThanF x)
  1516(GreaterEqualF    (InvertFlags x)) => (LessEqualF x)
  1517(LessThanNoov     (InvertFlags x)) => (CSEL0 [OpARM64NotEqual] (GreaterEqualNoov <typ.Bool> x) x)
  1518(GreaterEqualNoov (InvertFlags x)) => (CSINC [OpARM64NotEqual] (LessThanNoov <typ.Bool> x) (MOVDconst [0]) x)
  1519
  1520// Don't bother extending if we're not using the higher bits.
  1521(MOV(B|BU)reg x) && v.Type.Size() <= 1 => x
  1522(MOV(H|HU)reg x) && v.Type.Size() <= 2 => x
  1523(MOV(W|WU)reg x) && v.Type.Size() <= 4 => x
  1524
  1525// omit sign extension
  1526(MOVWreg <t> (ANDconst x [c])) && uint64(c) & uint64(0xffffffff80000000) == 0 => (ANDconst <t> x [c])
  1527(MOVHreg <t> (ANDconst x [c])) && uint64(c) & uint64(0xffffffffffff8000) == 0 => (ANDconst <t> x [c])
  1528(MOVBreg <t> (ANDconst x [c])) && uint64(c) & uint64(0xffffffffffffff80) == 0 => (ANDconst <t> x [c])
  1529
  1530// absorb flag constants into conditional instructions
  1531(CSEL  [cc] x _ flag) && ccARM64Eval(cc, flag) > 0 => x
  1532(CSEL  [cc] _ y flag) && ccARM64Eval(cc, flag) < 0 => y
  1533(CSEL0 [cc] x   flag) && ccARM64Eval(cc, flag) > 0 => x
  1534(CSEL0 [cc] _   flag) && ccARM64Eval(cc, flag) < 0 => (MOVDconst [0])
  1535(CSNEG [cc] x _ flag) && ccARM64Eval(cc, flag) > 0 => x
  1536(CSNEG [cc] _ y flag) && ccARM64Eval(cc, flag) < 0 => (NEG y)
  1537(CSINV [cc] x _ flag) && ccARM64Eval(cc, flag) > 0 => x
  1538(CSINV [cc] _ y flag) && ccARM64Eval(cc, flag) < 0 => (Not y)
  1539(CSINC [cc] x _ flag) && ccARM64Eval(cc, flag) > 0 => x
  1540(CSINC [cc] _ y flag) && ccARM64Eval(cc, flag) < 0 => (ADDconst [1] y)
  1541(CSETM [cc]     flag) && ccARM64Eval(cc, flag) > 0 => (MOVDconst [-1])
  1542(CSETM [cc]     flag) && ccARM64Eval(cc, flag) < 0 => (MOVDconst [0])
  1543
  1544// absorb flags back into boolean CSEL
  1545(CSEL [cc] x y (CMPWconst [0] boolval)) && cc == OpARM64NotEqual && flagArg(boolval) != nil =>
  1546      (CSEL [boolval.Op] x y flagArg(boolval))
  1547(CSEL [cc] x y (CMPWconst [0] boolval)) && cc == OpARM64Equal && flagArg(boolval) != nil =>
  1548      (CSEL [arm64Negate(boolval.Op)] x y flagArg(boolval))
  1549(CSEL0 [cc] x (CMPWconst [0] boolval)) && cc == OpARM64NotEqual && flagArg(boolval) != nil =>
  1550      (CSEL0 [boolval.Op] x flagArg(boolval))
  1551(CSEL0 [cc] x (CMPWconst [0] boolval)) && cc == OpARM64Equal && flagArg(boolval) != nil =>
  1552      (CSEL0 [arm64Negate(boolval.Op)] x flagArg(boolval))
  1553
  1554// absorb shifts into ops
  1555(NEG x:(SLLconst [c] y)) && clobberIfDead(x) => (NEGshiftLL [c] y)
  1556(NEG x:(SRLconst [c] y)) && clobberIfDead(x) => (NEGshiftRL [c] y)
  1557(NEG x:(SRAconst [c] y)) && clobberIfDead(x) => (NEGshiftRA [c] y)
  1558(MVN x:(SLLconst [c] y)) && clobberIfDead(x) => (MVNshiftLL [c] y)
  1559(MVN x:(SRLconst [c] y)) && clobberIfDead(x) => (MVNshiftRL [c] y)
  1560(MVN x:(SRAconst [c] y)) && clobberIfDead(x) => (MVNshiftRA [c] y)
  1561(MVN x:(RORconst [c] y)) && clobberIfDead(x) => (MVNshiftRO [c] y)
  1562(ADD x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (ADDshiftLL x0 y [c])
  1563(ADD x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (ADDshiftRL x0 y [c])
  1564(ADD x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (ADDshiftRA x0 y [c])
  1565(SUB x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (SUBshiftLL x0 y [c])
  1566(SUB x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (SUBshiftRL x0 y [c])
  1567(SUB x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (SUBshiftRA x0 y [c])
  1568(AND x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (ANDshiftLL x0 y [c])
  1569(AND x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (ANDshiftRL x0 y [c])
  1570(AND x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (ANDshiftRA x0 y [c])
  1571(AND x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (ANDshiftRO x0 y [c])
  1572(OR  x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (ORshiftLL  x0 y [c]) // useful for combined load
  1573(OR  x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (ORshiftRL  x0 y [c])
  1574(OR  x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (ORshiftRA  x0 y [c])
  1575(OR  x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (ORshiftRO  x0 y [c])
  1576(XOR x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (XORshiftLL x0 y [c])
  1577(XOR x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (XORshiftRL x0 y [c])
  1578(XOR x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (XORshiftRA x0 y [c])
  1579(XOR x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (XORshiftRO x0 y [c])
  1580(BIC x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (BICshiftLL x0 y [c])
  1581(BIC x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (BICshiftRL x0 y [c])
  1582(BIC x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (BICshiftRA x0 y [c])
  1583(BIC x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (BICshiftRO x0 y [c])
  1584(ORN x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (ORNshiftLL x0 y [c])
  1585(ORN x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (ORNshiftRL x0 y [c])
  1586(ORN x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (ORNshiftRA x0 y [c])
  1587(ORN x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (ORNshiftRO x0 y [c])
  1588(EON x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (EONshiftLL x0 y [c])
  1589(EON x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (EONshiftRL x0 y [c])
  1590(EON x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (EONshiftRA x0 y [c])
  1591(EON x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (EONshiftRO x0 y [c])
  1592(CMP x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (CMPshiftLL x0 y [c])
  1593(CMP x0:(SLLconst [c] y) x1) && clobberIfDead(x0) => (InvertFlags (CMPshiftLL x1 y [c]))
  1594(CMP x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (CMPshiftRL x0 y [c])
  1595(CMP x0:(SRLconst [c] y) x1) && clobberIfDead(x0) => (InvertFlags (CMPshiftRL x1 y [c]))
  1596(CMP x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (CMPshiftRA x0 y [c])
  1597(CMP x0:(SRAconst [c] y) x1) && clobberIfDead(x0) => (InvertFlags (CMPshiftRA x1 y [c]))
  1598(CMN x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (CMNshiftLL x0 y [c])
  1599(CMN x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (CMNshiftRL x0 y [c])
  1600(CMN x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (CMNshiftRA x0 y [c])
  1601(TST x0 x1:(SLLconst [c] y)) && clobberIfDead(x1) => (TSTshiftLL x0 y [c])
  1602(TST x0 x1:(SRLconst [c] y)) && clobberIfDead(x1) => (TSTshiftRL x0 y [c])
  1603(TST x0 x1:(SRAconst [c] y)) && clobberIfDead(x1) => (TSTshiftRA x0 y [c])
  1604(TST x0 x1:(RORconst [c] y)) && clobberIfDead(x1) => (TSTshiftRO x0 y [c])
  1605
  1606// prefer *const ops to *shift ops
  1607(ADDshiftLL (MOVDconst [c]) x [d]) => (ADDconst [c] (SLLconst <x.Type> x [d]))
  1608(ADDshiftRL (MOVDconst [c]) x [d]) => (ADDconst [c] (SRLconst <x.Type> x [d]))
  1609(ADDshiftRA (MOVDconst [c]) x [d]) => (ADDconst [c] (SRAconst <x.Type> x [d]))
  1610(ANDshiftLL (MOVDconst [c]) x [d]) => (ANDconst [c] (SLLconst <x.Type> x [d]))
  1611(ANDshiftRL (MOVDconst [c]) x [d]) => (ANDconst [c] (SRLconst <x.Type> x [d]))
  1612(ANDshiftRA (MOVDconst [c]) x [d]) => (ANDconst [c] (SRAconst <x.Type> x [d]))
  1613(ANDshiftRO (MOVDconst [c]) x [d]) => (ANDconst [c] (RORconst <x.Type> x [d]))
  1614(ORshiftLL  (MOVDconst [c]) x [d]) => (ORconst  [c] (SLLconst <x.Type> x [d]))
  1615(ORshiftRL  (MOVDconst [c]) x [d]) => (ORconst  [c] (SRLconst <x.Type> x [d]))
  1616(ORshiftRA  (MOVDconst [c]) x [d]) => (ORconst  [c] (SRAconst <x.Type> x [d]))
  1617(ORshiftRO  (MOVDconst [c]) x [d]) => (ORconst  [c] (RORconst <x.Type> x [d]))
  1618(XORshiftLL (MOVDconst [c]) x [d]) => (XORconst [c] (SLLconst <x.Type> x [d]))
  1619(XORshiftRL (MOVDconst [c]) x [d]) => (XORconst [c] (SRLconst <x.Type> x [d]))
  1620(XORshiftRA (MOVDconst [c]) x [d]) => (XORconst [c] (SRAconst <x.Type> x [d]))
  1621(XORshiftRO (MOVDconst [c]) x [d]) => (XORconst [c] (RORconst <x.Type> x [d]))
  1622(CMPshiftLL (MOVDconst [c]) x [d]) => (InvertFlags (CMPconst [c] (SLLconst <x.Type> x [d])))
  1623(CMPshiftRL (MOVDconst [c]) x [d]) => (InvertFlags (CMPconst [c] (SRLconst <x.Type> x [d])))
  1624(CMPshiftRA (MOVDconst [c]) x [d]) => (InvertFlags (CMPconst [c] (SRAconst <x.Type> x [d])))
  1625(CMNshiftLL (MOVDconst [c]) x [d]) => (CMNconst [c] (SLLconst <x.Type> x [d]))
  1626(CMNshiftRL (MOVDconst [c]) x [d]) => (CMNconst [c] (SRLconst <x.Type> x [d]))
  1627(CMNshiftRA (MOVDconst [c]) x [d]) => (CMNconst [c] (SRAconst <x.Type> x [d]))
  1628(TSTshiftLL (MOVDconst [c]) x [d]) => (TSTconst [c] (SLLconst <x.Type> x [d]))
  1629(TSTshiftRL (MOVDconst [c]) x [d]) => (TSTconst [c] (SRLconst <x.Type> x [d]))
  1630(TSTshiftRA (MOVDconst [c]) x [d]) => (TSTconst [c] (SRAconst <x.Type> x [d]))
  1631(TSTshiftRO (MOVDconst [c]) x [d]) => (TSTconst [c] (RORconst <x.Type> x [d]))
  1632
  1633// constant folding in *shift ops
  1634(MVNshiftLL (MOVDconst [c]) [d]) => (MOVDconst [^int64(uint64(c)<<uint64(d))])
  1635(MVNshiftRL (MOVDconst [c]) [d]) => (MOVDconst [^int64(uint64(c)>>uint64(d))])
  1636(MVNshiftRA (MOVDconst [c]) [d]) => (MOVDconst [^(c>>uint64(d))])
  1637(MVNshiftRO (MOVDconst [c]) [d]) => (MOVDconst [^rotateRight64(c, d)])
  1638(NEGshiftLL (MOVDconst [c]) [d]) => (MOVDconst [-int64(uint64(c)<<uint64(d))])
  1639(NEGshiftRL (MOVDconst [c]) [d]) => (MOVDconst [-int64(uint64(c)>>uint64(d))])
  1640(NEGshiftRA (MOVDconst [c]) [d]) => (MOVDconst [-(c>>uint64(d))])
  1641(ADDshiftLL x (MOVDconst [c]) [d]) => (ADDconst x [int64(uint64(c)<<uint64(d))])
  1642(ADDshiftRL x (MOVDconst [c]) [d]) => (ADDconst x [int64(uint64(c)>>uint64(d))])
  1643(ADDshiftRA x (MOVDconst [c]) [d]) => (ADDconst x [c>>uint64(d)])
  1644(SUBshiftLL x (MOVDconst [c]) [d]) => (SUBconst x [int64(uint64(c)<<uint64(d))])
  1645(SUBshiftRL x (MOVDconst [c]) [d]) => (SUBconst x [int64(uint64(c)>>uint64(d))])
  1646(SUBshiftRA x (MOVDconst [c]) [d]) => (SUBconst x [c>>uint64(d)])
  1647(ANDshiftLL x (MOVDconst [c]) [d]) => (ANDconst x [int64(uint64(c)<<uint64(d))])
  1648(ANDshiftRL x (MOVDconst [c]) [d]) => (ANDconst x [int64(uint64(c)>>uint64(d))])
  1649(ANDshiftRA x (MOVDconst [c]) [d]) => (ANDconst x [c>>uint64(d)])
  1650(ANDshiftRO x (MOVDconst [c]) [d]) => (ANDconst x [rotateRight64(c, d)])
  1651(ORshiftLL  x (MOVDconst [c]) [d]) => (ORconst  x [int64(uint64(c)<<uint64(d))])
  1652(ORshiftRL  x (MOVDconst [c]) [d]) => (ORconst  x [int64(uint64(c)>>uint64(d))])
  1653(ORshiftRA  x (MOVDconst [c]) [d]) => (ORconst  x [c>>uint64(d)])
  1654(ORshiftRO  x (MOVDconst [c]) [d]) => (ORconst  x [rotateRight64(c, d)])
  1655(XORshiftLL x (MOVDconst [c]) [d]) => (XORconst x [int64(uint64(c)<<uint64(d))])
  1656(XORshiftRL x (MOVDconst [c]) [d]) => (XORconst x [int64(uint64(c)>>uint64(d))])
  1657(XORshiftRA x (MOVDconst [c]) [d]) => (XORconst x [c>>uint64(d)])
  1658(XORshiftRO x (MOVDconst [c]) [d]) => (XORconst x [rotateRight64(c, d)])
  1659(BICshiftLL x (MOVDconst [c]) [d]) => (ANDconst x [^int64(uint64(c)<<uint64(d))])
  1660(BICshiftRL x (MOVDconst [c]) [d]) => (ANDconst x [^int64(uint64(c)>>uint64(d))])
  1661(BICshiftRA x (MOVDconst [c]) [d]) => (ANDconst x [^(c>>uint64(d))])
  1662(BICshiftRO x (MOVDconst [c]) [d]) => (ANDconst x [^rotateRight64(c, d)])
  1663(ORNshiftLL x (MOVDconst [c]) [d]) => (ORconst  x [^int64(uint64(c)<<uint64(d))])
  1664(ORNshiftRL x (MOVDconst [c]) [d]) => (ORconst  x [^int64(uint64(c)>>uint64(d))])
  1665(ORNshiftRA x (MOVDconst [c]) [d]) => (ORconst  x [^(c>>uint64(d))])
  1666(ORNshiftRO x (MOVDconst [c]) [d]) => (ORconst  x [^rotateRight64(c, d)])
  1667(EONshiftLL x (MOVDconst [c]) [d]) => (XORconst x [^int64(uint64(c)<<uint64(d))])
  1668(EONshiftRL x (MOVDconst [c]) [d]) => (XORconst x [^int64(uint64(c)>>uint64(d))])
  1669(EONshiftRA x (MOVDconst [c]) [d]) => (XORconst x [^(c>>uint64(d))])
  1670(EONshiftRO x (MOVDconst [c]) [d]) => (XORconst x [^rotateRight64(c, d)])
  1671(CMPshiftLL x (MOVDconst [c]) [d]) => (CMPconst x [int64(uint64(c)<<uint64(d))])
  1672(CMPshiftRL x (MOVDconst [c]) [d]) => (CMPconst x [int64(uint64(c)>>uint64(d))])
  1673(CMPshiftRA x (MOVDconst [c]) [d]) => (CMPconst x [c>>uint64(d)])
  1674(CMNshiftLL x (MOVDconst [c]) [d]) => (CMNconst x [int64(uint64(c)<<uint64(d))])
  1675(CMNshiftRL x (MOVDconst [c]) [d]) => (CMNconst x [int64(uint64(c)>>uint64(d))])
  1676(CMNshiftRA x (MOVDconst [c]) [d]) => (CMNconst x [c>>uint64(d)])
  1677(TSTshiftLL x (MOVDconst [c]) [d]) => (TSTconst x [int64(uint64(c)<<uint64(d))])
  1678(TSTshiftRL x (MOVDconst [c]) [d]) => (TSTconst x [int64(uint64(c)>>uint64(d))])
  1679(TSTshiftRA x (MOVDconst [c]) [d]) => (TSTconst x [c>>uint64(d)])
  1680(TSTshiftRO x (MOVDconst [c]) [d]) => (TSTconst x [rotateRight64(c, d)])
  1681
  1682// simplification with *shift ops
  1683(SUBshiftLL (SLLconst x [c]) x [c]) => (MOVDconst [0])
  1684(SUBshiftRL (SRLconst x [c]) x [c]) => (MOVDconst [0])
  1685(SUBshiftRA (SRAconst x [c]) x [c]) => (MOVDconst [0])
  1686(ANDshiftLL y:(SLLconst x [c]) x [c]) => y
  1687(ANDshiftRL y:(SRLconst x [c]) x [c]) => y
  1688(ANDshiftRA y:(SRAconst x [c]) x [c]) => y
  1689(ANDshiftRO y:(RORconst x [c]) x [c]) => y
  1690(ORshiftLL  y:(SLLconst x [c]) x [c]) => y
  1691(ORshiftRL  y:(SRLconst x [c]) x [c]) => y
  1692(ORshiftRA  y:(SRAconst x [c]) x [c]) => y
  1693(ORshiftRO  y:(RORconst x [c]) x [c]) => y
  1694(XORshiftLL (SLLconst x [c]) x [c]) => (MOVDconst [0])
  1695(XORshiftRL (SRLconst x [c]) x [c]) => (MOVDconst [0])
  1696(XORshiftRA (SRAconst x [c]) x [c]) => (MOVDconst [0])
  1697(XORshiftRO (RORconst x [c]) x [c]) => (MOVDconst [0])
  1698(BICshiftLL (SLLconst x [c]) x [c]) => (MOVDconst [0])
  1699(BICshiftRL (SRLconst x [c]) x [c]) => (MOVDconst [0])
  1700(BICshiftRA (SRAconst x [c]) x [c]) => (MOVDconst [0])
  1701(BICshiftRO (RORconst x [c]) x [c]) => (MOVDconst [0])
  1702(EONshiftLL (SLLconst x [c]) x [c]) => (MOVDconst [-1])
  1703(EONshiftRL (SRLconst x [c]) x [c]) => (MOVDconst [-1])
  1704(EONshiftRA (SRAconst x [c]) x [c]) => (MOVDconst [-1])
  1705(EONshiftRO (RORconst x [c]) x [c]) => (MOVDconst [-1])
  1706(ORNshiftLL (SLLconst x [c]) x [c]) => (MOVDconst [-1])
  1707(ORNshiftRL (SRLconst x [c]) x [c]) => (MOVDconst [-1])
  1708(ORNshiftRA (SRAconst x [c]) x [c]) => (MOVDconst [-1])
  1709(ORNshiftRO (RORconst x [c]) x [c]) => (MOVDconst [-1])
  1710
  1711// rev16w | rev16
  1712// ((x>>8) | (x<<8)) => (REV16W x), the type of x is uint16, "|" can also be "^" or "+".
  1713((ADDshiftLL|ORshiftLL|XORshiftLL) <typ.UInt16> [8] (UBFX <typ.UInt16> [armBFAuxInt(8, 8)] x) x) => (REV16W x)
  1714
  1715// ((x & 0xff00ff00)>>8) | ((x & 0x00ff00ff)<<8), "|" can also be "^" or "+".
  1716((ADDshiftLL|ORshiftLL|XORshiftLL) [8] (UBFX [armBFAuxInt(8, 24)] (ANDconst [c1] x)) (ANDconst [c2] x))
  1717	&& uint32(c1) == 0xff00ff00 && uint32(c2) == 0x00ff00ff
  1718	=> (REV16W x)
  1719
  1720// ((x & 0xff00ff00ff00ff00)>>8) | ((x & 0x00ff00ff00ff00ff)<<8), "|" can also be "^" or "+".
  1721((ADDshiftLL|ORshiftLL|XORshiftLL) [8] (SRLconst [8] (ANDconst [c1] x)) (ANDconst [c2] x))
  1722	&& (uint64(c1) == 0xff00ff00ff00ff00 && uint64(c2) == 0x00ff00ff00ff00ff)
  1723	=> (REV16 x)
  1724
  1725// ((x & 0xff00ff00)>>8) | ((x & 0x00ff00ff)<<8), "|" can also be "^" or "+".
  1726((ADDshiftLL|ORshiftLL|XORshiftLL) [8] (SRLconst [8] (ANDconst [c1] x)) (ANDconst [c2] x))
  1727	&& (uint64(c1) == 0xff00ff00 && uint64(c2) == 0x00ff00ff)
  1728	=> (REV16 (ANDconst <x.Type> [0xffffffff] x))
  1729
  1730// Extract from reg pair
  1731(ADDshiftLL [c] (SRLconst x [64-c]) x2) => (EXTRconst [64-c] x2 x)
  1732( ORshiftLL [c] (SRLconst x [64-c]) x2) => (EXTRconst [64-c] x2 x)
  1733(XORshiftLL [c] (SRLconst x [64-c]) x2) => (EXTRconst [64-c] x2 x)
  1734
  1735(ADDshiftLL <t> [c] (UBFX [bfc] x) x2) && c < 32 && t.Size() == 4 && bfc == armBFAuxInt(32-c, c)
  1736	=> (EXTRWconst [32-c] x2 x)
  1737( ORshiftLL <t> [c] (UBFX [bfc] x) x2) && c < 32 && t.Size() == 4 && bfc == armBFAuxInt(32-c, c)
  1738	=> (EXTRWconst [32-c] x2 x)
  1739(XORshiftLL <t> [c] (UBFX [bfc] x) x2) && c < 32 && t.Size() == 4 && bfc == armBFAuxInt(32-c, c)
  1740	=> (EXTRWconst [32-c] x2 x)
  1741
  1742// Rewrite special pairs of shifts to AND.
  1743// On ARM64 the bitmask can fit into an instruction.
  1744(SRLconst [c] (SLLconst [c] x)) && 0 < c && c < 64 => (ANDconst [1<<uint(64-c)-1] x) // mask out high bits
  1745(SLLconst [c] (SRLconst [c] x)) && 0 < c && c < 64 => (ANDconst [^(1<<uint(c)-1)] x) // mask out low bits
  1746
  1747// Special case setting bit as 1. An example is math.Copysign(c,-1)
  1748(ORconst [c1] (ANDconst [c2] x)) && c2|c1 == ^0  => (ORconst [c1] x)
  1749
  1750// If the shift amount is larger than the datasize(32, 16, 8), we can optimize to constant 0.
  1751(MOVWUreg (SLLconst [lc] x)) && lc >= 32 => (MOVDconst [0])
  1752(MOVHUreg (SLLconst [lc] x)) && lc >= 16 => (MOVDconst [0])
  1753(MOVBUreg (SLLconst [lc] x)) && lc >= 8 => (MOVDconst [0])
  1754
  1755// After zero extension, the upper (64-datasize(32|16|8)) bits are zero, we can optimiza to constant 0.
  1756(SRLconst [rc] (MOVWUreg x)) && rc >= 32 => (MOVDconst [0])
  1757(SRLconst [rc] (MOVHUreg x)) && rc >= 16 => (MOVDconst [0])
  1758(SRLconst [rc] (MOVBUreg x)) && rc >= 8 => (MOVDconst [0])
  1759
  1760// bitfield ops
  1761
  1762// sbfiz
  1763// (x << lc) >> rc
  1764(SRAconst [rc] (SLLconst [lc] x)) && lc > rc => (SBFIZ [armBFAuxInt(lc-rc, 64-lc)] x)
  1765// int64(x << lc)
  1766(MOVWreg (SLLconst [lc] x)) && lc < 32 => (SBFIZ [armBFAuxInt(lc, 32-lc)] x)
  1767(MOVHreg (SLLconst [lc] x)) && lc < 16 => (SBFIZ [armBFAuxInt(lc, 16-lc)] x)
  1768(MOVBreg (SLLconst [lc] x)) && lc < 8  => (SBFIZ [armBFAuxInt(lc,  8-lc)] x)
  1769// int64(x) << lc
  1770(SLLconst [lc] (MOVWreg x))  => (SBFIZ [armBFAuxInt(lc, min(32, 64-lc))] x)
  1771(SLLconst [lc] (MOVHreg x))  => (SBFIZ [armBFAuxInt(lc, min(16, 64-lc))] x)
  1772(SLLconst [lc] (MOVBreg x))  => (SBFIZ [armBFAuxInt(lc, min(8,  64-lc))] x)
  1773
  1774// sbfx
  1775// (x << lc) >> rc
  1776(SRAconst [rc] (SLLconst [lc] x)) && lc <= rc => (SBFX [armBFAuxInt(rc-lc, 64-rc)] x)
  1777// int64(x) >> rc
  1778(SRAconst [rc] (MOVWreg x)) && rc < 32 => (SBFX [armBFAuxInt(rc, 32-rc)] x)
  1779(SRAconst [rc] (MOVHreg x)) && rc < 16 => (SBFX [armBFAuxInt(rc, 16-rc)] x)
  1780(SRAconst [rc] (MOVBreg x)) && rc < 8  => (SBFX [armBFAuxInt(rc,  8-rc)] x)
  1781// merge sbfx and sign-extension into sbfx
  1782(MOVWreg (SBFX [bfc] x)) && bfc.getARM64BFwidth() <= 32 => (SBFX [bfc] x)
  1783(MOVHreg (SBFX [bfc] x)) && bfc.getARM64BFwidth() <= 16 => (SBFX [bfc] x)
  1784(MOVBreg (SBFX [bfc] x)) && bfc.getARM64BFwidth() <=  8 => (SBFX [bfc] x)
  1785
  1786// sbfiz/sbfx combinations: merge shifts into bitfield ops
  1787(SRAconst [sc] (SBFIZ [bfc] x)) && sc < bfc.getARM64BFlsb()
  1788	=> (SBFIZ [armBFAuxInt(bfc.getARM64BFlsb()-sc, bfc.getARM64BFwidth())] x)
  1789(SRAconst [sc] (SBFIZ [bfc] x)) && sc >= bfc.getARM64BFlsb()
  1790	&& sc < bfc.getARM64BFlsb()+bfc.getARM64BFwidth()
  1791	=> (SBFX [armBFAuxInt(sc-bfc.getARM64BFlsb(), bfc.getARM64BFlsb()+bfc.getARM64BFwidth()-sc)] x)
  1792
  1793// ubfiz
  1794// (x << lc) >> rc
  1795(SRLconst [rc] (SLLconst [lc] x)) && lc > rc => (UBFIZ [armBFAuxInt(lc-rc, 64-lc)] x)
  1796// uint64(x) << lc
  1797(SLLconst [lc] (MOVWUreg x))  => (UBFIZ [armBFAuxInt(lc, min(32, 64-lc))] x)
  1798(SLLconst [lc] (MOVHUreg x))  => (UBFIZ [armBFAuxInt(lc, min(16, 64-lc))] x)
  1799(SLLconst [lc] (MOVBUreg x))  => (UBFIZ [armBFAuxInt(lc, min(8,  64-lc))] x)
  1800// uint64(x << lc)
  1801(MOVWUreg (SLLconst [lc] x)) && lc < 32 => (UBFIZ [armBFAuxInt(lc, 32-lc)] x)
  1802(MOVHUreg (SLLconst [lc] x)) && lc < 16 => (UBFIZ [armBFAuxInt(lc, 16-lc)] x)
  1803(MOVBUreg (SLLconst [lc] x)) && lc < 8  => (UBFIZ [armBFAuxInt(lc,  8-lc)] x)
  1804
  1805// merge ANDconst into ubfiz
  1806// (x & ac) << sc
  1807(SLLconst [sc] (ANDconst [ac] x)) && isARM64BFMask(sc, ac, 0)
  1808	=> (UBFIZ [armBFAuxInt(sc, arm64BFWidth(ac, 0))] x)
  1809// (x << sc) & ac
  1810(ANDconst [ac] (SLLconst [sc] x)) && isARM64BFMask(sc, ac, sc)
  1811	=> (UBFIZ [armBFAuxInt(sc, arm64BFWidth(ac, sc))] x)
  1812
  1813// ubfx
  1814// (x << lc) >> rc
  1815(SRLconst [rc] (SLLconst [lc] x)) && lc < rc => (UBFX [armBFAuxInt(rc-lc, 64-rc)] x)
  1816// uint64(x) >> rc
  1817(SRLconst [rc] (MOVWUreg x)) && rc < 32 => (UBFX [armBFAuxInt(rc, 32-rc)] x)
  1818(SRLconst [rc] (MOVHUreg x)) && rc < 16 => (UBFX [armBFAuxInt(rc, 16-rc)] x)
  1819(SRLconst [rc] (MOVBUreg x)) && rc < 8  => (UBFX [armBFAuxInt(rc,  8-rc)] x)
  1820// uint64(x >> rc)
  1821(MOVWUreg (SRLconst [rc] x)) && rc < 32 => (UBFX [armBFAuxInt(rc, 32)] x)
  1822(MOVHUreg (SRLconst [rc] x)) && rc < 16 => (UBFX [armBFAuxInt(rc, 16)] x)
  1823(MOVBUreg (SRLconst [rc] x)) && rc < 8  => (UBFX [armBFAuxInt(rc,  8)] x)
  1824// merge ANDconst into ubfx
  1825// (x >> sc) & ac
  1826(ANDconst [ac] (SRLconst [sc] x)) && isARM64BFMask(sc, ac, 0)
  1827	=> (UBFX [armBFAuxInt(sc, arm64BFWidth(ac, 0))] x)
  1828// (x & ac) >> sc
  1829(SRLconst [sc] (ANDconst [ac] x)) && isARM64BFMask(sc, ac, sc)
  1830	=> (UBFX [armBFAuxInt(sc, arm64BFWidth(ac, sc))] x)
  1831// merge ANDconst and ubfx into ubfx
  1832(ANDconst [c] (UBFX [bfc] x)) && isARM64BFMask(0, c, 0) =>
  1833	(UBFX [armBFAuxInt(bfc.getARM64BFlsb(), min(bfc.getARM64BFwidth(), arm64BFWidth(c, 0)))] x)
  1834(UBFX [bfc] (ANDconst [c] x)) && isARM64BFMask(0, c, 0) && bfc.getARM64BFlsb() + bfc.getARM64BFwidth() <= arm64BFWidth(c, 0) =>
  1835	(UBFX [bfc] x)
  1836// merge ubfx and zerso-extension into ubfx
  1837(MOVWUreg (UBFX [bfc] x)) && bfc.getARM64BFwidth() <= 32 => (UBFX [bfc] x)
  1838(MOVHUreg (UBFX [bfc] x)) && bfc.getARM64BFwidth() <= 16 => (UBFX [bfc] x)
  1839(MOVBUreg (UBFX [bfc] x)) && bfc.getARM64BFwidth() <=  8 => (UBFX [bfc] x)
  1840
  1841// ubfiz/ubfx combinations: merge shifts into bitfield ops
  1842(SRLconst [sc] (UBFX [bfc] x)) && sc < bfc.getARM64BFwidth()
  1843	=> (UBFX [armBFAuxInt(bfc.getARM64BFlsb()+sc, bfc.getARM64BFwidth()-sc)] x)
  1844(UBFX [bfc] (SRLconst [sc] x)) && sc+bfc.getARM64BFwidth()+bfc.getARM64BFlsb() < 64
  1845	=> (UBFX [armBFAuxInt(bfc.getARM64BFlsb()+sc, bfc.getARM64BFwidth())] x)
  1846(SLLconst [sc] (UBFIZ [bfc] x)) && sc+bfc.getARM64BFwidth()+bfc.getARM64BFlsb() < 64
  1847	=> (UBFIZ [armBFAuxInt(bfc.getARM64BFlsb()+sc, bfc.getARM64BFwidth())] x)
  1848(UBFIZ [bfc] (SLLconst [sc] x)) && sc < bfc.getARM64BFwidth()
  1849	=> (UBFIZ [armBFAuxInt(bfc.getARM64BFlsb()+sc, bfc.getARM64BFwidth()-sc)] x)
  1850// ((x << c1) >> c2) >> c3
  1851(SRLconst [sc] (UBFIZ [bfc] x)) && sc == bfc.getARM64BFlsb()
  1852	=> (ANDconst [1<<uint(bfc.getARM64BFwidth())-1] x)
  1853(SRLconst [sc] (UBFIZ [bfc] x)) && sc < bfc.getARM64BFlsb()
  1854	=> (UBFIZ [armBFAuxInt(bfc.getARM64BFlsb()-sc, bfc.getARM64BFwidth())] x)
  1855(SRLconst [sc] (UBFIZ [bfc] x)) && sc > bfc.getARM64BFlsb()
  1856	&& sc < bfc.getARM64BFlsb()+bfc.getARM64BFwidth()
  1857	=> (UBFX [armBFAuxInt(sc-bfc.getARM64BFlsb(), bfc.getARM64BFlsb()+bfc.getARM64BFwidth()-sc)] x)
  1858// ((x << c1) << c2) >> c3
  1859(UBFX [bfc] (SLLconst [sc] x)) && sc == bfc.getARM64BFlsb()
  1860	=> (ANDconst [1<<uint(bfc.getARM64BFwidth())-1] x)
  1861(UBFX [bfc] (SLLconst [sc] x)) && sc < bfc.getARM64BFlsb()
  1862	=> (UBFX [armBFAuxInt(bfc.getARM64BFlsb()-sc, bfc.getARM64BFwidth())] x)
  1863(UBFX [bfc] (SLLconst [sc] x)) && sc > bfc.getARM64BFlsb()
  1864	&& sc < bfc.getARM64BFlsb()+bfc.getARM64BFwidth()
  1865	=> (UBFIZ [armBFAuxInt(sc-bfc.getARM64BFlsb(), bfc.getARM64BFlsb()+bfc.getARM64BFwidth()-sc)] x)
  1866
  1867// bfi
  1868(OR (UBFIZ [bfc] x) (ANDconst [ac] y))
  1869	&& ac == ^((1<<uint(bfc.getARM64BFwidth())-1) << uint(bfc.getARM64BFlsb()))
  1870	=> (BFI [bfc] y x)
  1871(ORshiftRL [rc] (ANDconst [ac] x) (SLLconst [lc] y))
  1872	&& lc > rc && ac == ^((1<<uint(64-lc)-1) << uint64(lc-rc))
  1873	=> (BFI [armBFAuxInt(lc-rc, 64-lc)] x y)
  1874// bfxil
  1875(OR (UBFX [bfc] x) (ANDconst [ac] y)) && ac == ^(1<<uint(bfc.getARM64BFwidth())-1)
  1876	=> (BFXIL [bfc] y x)
  1877(ORshiftLL [sc] (UBFX [bfc] x) (SRLconst [sc] y)) && sc == bfc.getARM64BFwidth()
  1878	=> (BFXIL [bfc] y x)
  1879(ORshiftRL [rc] (ANDconst [ac] y) (SLLconst [lc] x)) && lc < rc && ac == ^((1<<uint(64-rc)-1))
  1880	=> (BFXIL [armBFAuxInt(rc-lc, 64-rc)] y x)
  1881
  1882// FP simplification
  1883(FNEGS  (FMULS  x y)) => (FNMULS x y)
  1884(FNEGD  (FMULD  x y)) => (FNMULD x y)
  1885(FMULS  (FNEGS  x) y) => (FNMULS x y)
  1886(FMULD  (FNEGD  x) y) => (FNMULD x y)
  1887(FNEGS  (FNMULS x y)) => (FMULS  x y)
  1888(FNEGD  (FNMULD x y)) => (FMULD  x y)
  1889(FNMULS (FNEGS  x) y) => (FMULS  x y)
  1890(FNMULD (FNEGD  x) y) => (FMULD  x y)
  1891
  1892(FADDS a (FMULS  x y)) && a.Block.Func.useFMA(v) => (FMADDS  a x y)
  1893(FADDD a (FMULD  x y)) && a.Block.Func.useFMA(v) => (FMADDD  a x y)
  1894(FSUBS a (FMULS  x y)) && a.Block.Func.useFMA(v) => (FMSUBS  a x y)
  1895(FSUBD a (FMULD  x y)) && a.Block.Func.useFMA(v) => (FMSUBD  a x y)
  1896(FSUBS (FMULS  x y) a) && a.Block.Func.useFMA(v) => (FNMSUBS a x y)
  1897(FSUBD (FMULD  x y) a) && a.Block.Func.useFMA(v) => (FNMSUBD a x y)
  1898(FADDS a (FNMULS x y)) && a.Block.Func.useFMA(v) => (FMSUBS  a x y)
  1899(FADDD a (FNMULD x y)) && a.Block.Func.useFMA(v) => (FMSUBD  a x y)
  1900(FSUBS a (FNMULS x y)) && a.Block.Func.useFMA(v) => (FMADDS  a x y)
  1901(FSUBD a (FNMULD x y)) && a.Block.Func.useFMA(v) => (FMADDD  a x y)
  1902(FSUBS (FNMULS x y) a) && a.Block.Func.useFMA(v) => (FNMADDS a x y)
  1903(FSUBD (FNMULD x y) a) && a.Block.Func.useFMA(v) => (FNMADDD a x y)
  1904
  1905(MOVBUload [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(read8(sym, int64(off)))])
  1906(MOVHUload [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(read16(sym, int64(off), config.ctxt.Arch.ByteOrder))])
  1907(MOVWUload [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(read32(sym, int64(off), config.ctxt.Arch.ByteOrder))])
  1908(MOVDload  [off] {sym} (SB) _) && symIsRO(sym) => (MOVDconst [int64(read64(sym, int64(off), config.ctxt.Arch.ByteOrder))])
  1909
  1910// Prefetch instructions (aux is option: 0 - PLDL1KEEP; 1 - PLDL1STRM)
  1911(PrefetchCache addr mem)         => (PRFM [0] addr mem)
  1912(PrefetchCacheStreamed addr mem) => (PRFM [1] addr mem)
  1913
  1914// Arch-specific inlining for small or disjoint runtime.memmove
  1915(SelectN [0] call:(CALLstatic {sym} s1:(MOVDstore _ (MOVDconst [sz]) s2:(MOVDstore  _ src s3:(MOVDstore {t} _ dst mem)))))
  1916	&& sz >= 0
  1917	&& isSameCall(sym, "runtime.memmove")
  1918	&& s1.Uses == 1 && s2.Uses == 1 && s3.Uses == 1
  1919	&& isInlinableMemmove(dst, src, sz, config)
  1920	&& clobber(s1, s2, s3, call)
  1921	=> (Move [sz] dst src mem)
  1922
  1923// Match post-lowering calls, register version.
  1924(SelectN [0] call:(CALLstatic {sym} dst src (MOVDconst [sz]) mem))
  1925	&& sz >= 0
  1926	&& isSameCall(sym, "runtime.memmove")
  1927	&& call.Uses == 1
  1928	&& isInlinableMemmove(dst, src, sz, config)
  1929	&& clobber(call)
  1930	=> (Move [sz] dst src mem)
  1931
  1932((REV|REVW) ((REV|REVW) p)) => p
  1933
  1934// runtime/internal/math.MulUintptr intrinsics
  1935
  1936(Select0 (Mul64uover x y)) => (MUL x y)
  1937(Select1 (Mul64uover x y)) => (NotEqual (CMPconst (UMULH <typ.UInt64> x y) [0]))

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